EPA.PU480.PR. 5-532-6
:S FOR CONSTRUCTING
NDERGROUND
'JNJECTION OF PLASTICS
U; S. ENVIRONMENTAL PROTECTION AGENCY
OFflCE OF RESEARCH AND DEVOLOPMENT
ROBERT S.KERR ENVIRONMENTAL RESEARCH LABORATORY
ADA, OKLAHOMA 74820
-------
TECHNIQUES FOR CONSTRUCTING UNDERGROUND
BARRIERS BY INJECTION OF PLASTICS
By
Bolesiaw Jacenkow
Institute of Meteorology and Water Management
Warsaw, Poland
Project No PR-5-532-6
Project Officer
William C . G alegar
Robert S .Kerr Environmental Research Laboratory
Ada, Oklahoma 74820
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
ROBERT S.KERR ENVIRONMENTAL RESEARCH LABORATORY
ADA, OKLAHOMA 74820
-------
DISCLAIMER
This report has been reviewed by the Robert S. Kerr Environmental Rese-
arch Laboratory U.S. Environmental Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily reflect
the views and policies of the U.S. Environmental Protection Agency, nor
does mention of trade names or commercial products constitute endorsement
or recommendation for use .
11
-------
ABSTRACT
At the present state of development of industry and agriculture it is imposs-
ible to avoid, in many cases, the penetration of pollutants into the soil. One
of the basic method of the protection of underground waters against pollution
is confining the contaminated areas by means of vertical and horizontal
waterproof curtains. In recent year the procedure of carrying out the curtains
through the grouting of chemical components into the soil has been developed.
The method for synthesis of two types of resins (ureal-formaldehyde, modified
with pyrosulphate of sodium) has been elaborated, thus obtaining the resins
suitable to the grouting, of a viscosity close to that of water. A number of
hardeners on the basis on acid solutions or salts have been selected and exam-
ined. They enable to control the gelation time from a few minutes to tens of
hours. The obtained resin compositions endow the soil, after stabilization,
with strength from a few to 150 kg/cm-^ and decrease the permeability to
10'l^cm/sec. The aceton-formaldehyde and phenol-formaldehyde resins have
been also examined. Depending upon the composition, the resins can be
applied in acid, neutral and alkaline soils.
The investigations have been carried out with regard to ageing the stabilized
soil samples kept in water and on the air. The trials of explaining the process
of ageing and determining its factors have been made.
Mathematical model of the grouting process has been elaborated to- enable
performing the project of the grouting, selecting a suitable composition
of the grout as well as elaborating the technology of pumping.
A few series of laboratory and field investigations have beeii carried out for
determining the possibility of utilizing the elaborated resins for soil stabil-
ization. Bulbs, piles, rings, horizontal and vertical curtains have been
performed. The investigations have been done in watered and unwatered
soils, during confined or unconfined grout flov as well as in homogeneous
and heterogeneous soil media. The investigations have proved the correc-
tness of the elaborated mathematical model and showed the usefulness of
the elaborated grouts.
This report was submitted in fulfilment of the Project No. PR-5-532-G
by the Department of Underground Water Hydrodynamics, the Institute
of Meteorology and Water Management, under sponsorship of the Environ-
mental Protection Agency. Work was completed on 31. XII. 1975.
Ill
-------
CONTENTS
Sections Page
I Introduction 1
II Summary 2
III Conclusions 4
IV Recommendations 5
V Review of literature 6
VI Synthesis of low - viscosity urea formaldehyde resins
and their modification by sodic pyrosulphite and
properties of stabilized soils 12
VII Influence of plasticization of SP - modified UF resins
on properties of soils stabilized by them 47
VIII Ageing changes in soils stabilized by SP modified UF
resins 55
IX Basic grouts 82
X Methodology of investigation 98
XI Methods for computation of grout flow 107
XII Laboratory investigations of grouting process 131
XIII Field investigations 175
XIV References 200
XV Bibliography 205
XVI Appendix A . Printouts of programs for computations
of injection 206
XVII Appendix B. Photos of the blocks obtained on the laboratory
and field investigations of grouting 221
rv
-------
FIGURES
No
1 Soil limits for grout inject!vity
2 IR spectrum of colliodal deposit isolated from UF
resin (1) and hardened UF resin (2) 14
3 IR spectrum of hardened UF resin (1) and UF
resin modified by SP (2) 14
4 Function diagrams •t - f (Dr) for UF resin
modified by SP 22
5 The influence of F : U molar ratio during the
resin synthesis on the strength properties of the
samples of the stabilized soil ( before the stabili-
zation U was dissolved in the resin in quantity
indispensible to obtain molar ratio F : U = 2, 1 :l) 25
6 Dependence of compressive strength of soil
samples stabilized with UF resins modified by SP
on molar ratio F : U. 26
7 Influence of pH on gelling time 30 percent UF
resin solution modified by SP hardened with oxalic
acid 28
8 Gelling times of 30 percent UF resins ( F.-U.-SP =
2, 1 ;1:0, 003 ) hardened with ammonium chloride (1)
and ammonium chloride buffered with hexamethy-
lenetetramine (urotropin ) in quantities : 0, 5g (2) ,
l,0g(3), 2,0g(4), 3,0g(5). 4,0g(6) per 100ml
of resin 29
9 Gelling times of 30 percent UF resin solution
(F:U:SP = 2,1:1:0,049 ) hardened with ammonium
chloride(l) and ammonium chloride buffered with
hexamethylenetetramine ( urotropin ) in quantities :
0,5g(2), l,0g(3), 2,0g(4)) 3.0g(5), 4,0g(6),
per 100 ml of resin 30
10 Gelling times of 30 percent UF resin solution
(F:U:SP= 2,1:1:0, 003) hardened with ammonium
chloride buffered with thriethylenetetramine ( TETA)
in quantitied : 0, 5 ml (l) , 1 ml (2) , 1, 5 ml ( 3) ,
2, 5 ml (4 ) per 1 00 ml of resin 31
11 Gelling time of 30 percent UF resin solution (F:U:SP =
V \
= 2,1:1:0, 049) hardened with ammonium chloride
buffered with thriethylenetetramine TETA in quanti-
ties: 0, 5 ml(l), 1 ml (2 ), 1, 5 ml ( 3 ) , 2 ml (4 ) ,
2, 5 ml (5) , per 100 rnl of resin 32
V
-------
No Pag<
12 The inHuence of UF resin(F:U:SP = 2,1:1:0,003)
hardened with oxalic acid (1) , hydrochloric acid
buffered with monobasic ammonium phosphate (2)
and ammonium chloride ( 3 ) on gelling times 34
13 The influence of UF resins (F:U:SP = 2,1:1:0, 049)
hardened with oxalic acid (1 ) , hydrochloric and
buffered with monobasic ammonium phosphate ( 2 )
and ammonium chloride ( 3 ) on gelling times 35
14 Changes of viscosity during gelling time of 30 per-
cent UF resin solution (F;U:SP = 2, 1:1:0,049)
hardened with oxalic acid 37
15 Changes of viscosity of 30 percent UF resin solution
(F:U:SP = 2, 1 ;1:0, 049 ) during hardening with ammo-
nium chloride (1) and ammonium chloride buffered
with hexamethylenetetramine in quantitied 0, 5g(2),
2,0g(3) , and 4,0g(4) 38
16 Changes of viscosity ( 1) and pH ( 2 ) of 30 percent
UF resin solution (F:U:SP = 2,1:1:0,049) during
hardening with ammonium chloride buffered with
thriethylenetetramine 39
17 Compressive strength of soil samples stabilized
by UF resin modified by SP hardened with oxalic
acid 41
18 Coefficients of permeability k of soil samples
sealed with UF resin modified by SP hardened
by oxalic acid 42
19 Compressive strength of soil samples stabilized
with UF resin modified by SP hardened with
ammonium chloride 44
20 Hardened UF resin modified by PS of 30 percent
concentration ( F:U:SP - 2,1:0,003) filling the space
among 'sand grains. Enlargement 200 x. The picture
of microsection taken by differential method with
use of MPI - 5 microscope 45
21 The Compressive strength and the coefficient
of permeability of soil samples stabilized by SP
modified UF resin. The strength values for samples
stored in water (l) and in the open air ( 2), the coeffi-
cients of permeability k (3) 57
w
VI
-------
No
22 The compressive strength and the coefficient
of permeability of soil samples stabilized by SP =
modified UF resin of the molar ratio F : U : SP =
= 2,1:1:0,049. The compressive strength of samples
stored in water (l) , and in the open air (2 ) , the
coefficient of permeability of samples stored in wa-
ter k (3)
w ^ '
58
23 Changes of the compressive strength of soil samples
stabilized by UF resin hardened by various harde-
ners : oxalic acid ( 1 ) , ammonium chloride ("2) and
muriatic acid buffered by monobasic ammonium
phosphate (3) 59
24 Changes in the structure of the UF hardened resin
extracted by water molar ratio U:F (1) , K...
coefficient characterizing the cross-linkage rate of
the polymer, ( 2 ) , K coefficient characterizing the
number of methylol groups in the polymer (3) 63
25 Changes in the structure of the hardened UF resin
extracted by 0. 1 n solution of HC1, molar ratio
U;F(l), K. coefficient characterizing the cross-
linkage rate of the polymer (2), K» coefficient
characterizing the number of methylol groups in the
polymer (3) 64
26 Relative changes of the compressive strength of soil
samples stabilized by SP - modified UF resin stored
in water solutions of muriatic acid of various pH 67
27 The compressive strength of soil samples stabilized
by UF resin stored in water (l) and in water solutions
of formaldehyde of pH 1. 7 and concentration 2 per-
cent (2), 4 percent (3) and 6 percent (4). 70
28 Changes of the compressive strength of soil samples
of various size grain stabilized by UF resin in the
course of storage in water at the pH 1.7: 1 - fraction
0. 12 - 0. 30 mm, 2 -fraction 0. 30-0. 43 mm, 3-fraction
0. 43- 0. 60 mm 72
29 Diagram showing sites from which samples were
taken out of the soil block stabilized by means of grou-
ting under field conditions 75
VII
-------
No Page
30 Changes of the compressive strength (l) and the coeffi-
cient of permeability kw(2) and the organic matter
content (3) as a function of the distance from the axis
of the stabilized soil block 76
31 Changes of the structure of the hardened UF resin
as a function of the distance from the axis of the
stabilized soil block molar ratio U:F, [ij , K^
coefficient characterizing the cross-linkage rate
of the polymer, (2J , K^ coefficient characterizing
the number of methylol groups in the polymer (3) 78
32 Changes in the formaldehyde concentration (1), pH (2J
and the K^ coefficient characterizing the number
of methylol groups in the polymer (3) 80
33 Uniaxial compressive strength of the soil samples
stabilized with AF resins obtained at different F/A
molar ratio 84
34 Coefficient of permeability k for the soil samples
stabilized with AF resins obtained at different F/A
molar ratio 84
35 Dependence between the density and the content
of dry substance for AF-3P resin (hatched area
the range of grouting AF resins) 85
36 Dependence between viscosity and the content
of dry substance for AF-3P resin (hatched area -
the range of grouting AF resinsj 85
37 The influence of AF-3P resin dilution on the strength
of sandy soil stabilized with it (hatched area - the
range of grouting AF resins) 87
38 The course of viscosity changes of AF grout hardened
with different quantities of 25 percent NaOH solution 88
39 The course of viscosity changes of AF grout hardened
with 25 percent NaOH solution ( 25 part of hardener
volume per 100 part of AF - 31 resin volume ) in
temperature : 1 - 295, 5° - 0, 2°K, 2 - 290, 5° - 0, 2°K,
3 - 285,5° - 0,2°K, 4 - 280, 5° - 0, 2°K. 89
VIII
-------
No
40 Dependence of AF grout gelling time (AF-31 resin
hardened v/ith 25 percent NaOH solution in quantity
of 25 part of volume on the temperature ) 90
41 Dependence of mechanical resistance of stabilized
soil on the degree to which AF grout is dilute
with the hardener (25 percent water solution NaOHJ 91
42 Influence of ageing period on the mechanical
resistance of the soil samples stabilized with AF
grout 91
43 The influence of ageing period on the coefficient
of permeability k. of the soil samples stabilized
with AF grout 93
44 The course of viscosity changes of FF grout at
temperature 95
45 The influence of ageing period on the mechanical
resistance of the soil samples stabilized with
FF grout 96
46 The influence of ageing period on coefficient of
permeability k of the soil samples stabilized
with FF grout 96
47 Diagram of the semi - technical installation for AF
and UF resin production 100
48 Diagram of the installation for UF resin production 101
49 Diagram of the instrument for measuring the coeffi-
cient of permeability of samples 105
50 Pattern of the grouting procces 109
51 Dependence of time and of the injection rate on the
radius range r of the grout, according to the
pattern A [computation with the programme A l) 113
52 Dependence of the radius range r of the grout
and of the injection rate on the injection duration,
according to the pattern A ( computation with the
programme A 2j 114
53 Time discretization of the function k (t) 115
IX
-------
No
54 The axial-symmetrical ^ector of the filtration area
with situation in the j time step, for the pattern B 115
55 Flowchart of the program B 1 H9
56 Dependence of the radius range r^ and the rate
of the injection Q on the duration of the injection t,
for the pattern B (computation according to the
programme B l) I22
57 Dependence of the radius range r^ of the grout
the radius range of the dilating liquid r and of
the injection rate Q on the duration of the injection t
for the pattern B (computation according to the progra-
mme B 2) 123
58 Axial-symmetrical sector of the filtration area with
situation in the j time step, for the pattern C 124
59 Flowchart of the program C 1 127
60 Dependence of the radius range r'B of the grout
and the injection rate on the injection duration,
according to the pattern C (computation according
to the programme C l) . 129
61 Dependence of the radius range r^ of the grout
the radius range r of the dilating liquid and
the injection rate on the injection duration according
to the pattern C (computation according to the pro-
gramme C 2) 130
62 Basic shapes of the stabilized blocks by grouting 132
63 Model for investigation of the grouting 133
64 View of the model for investigation of the grouting 134
65 Models of the soil media to be injected 136
66 Method for injecting a bulb (pile) 137
67 Method for injecting a ring 138
68 Method for injecting a horizontal plate 139
69 Cross-sections of the bulbs obtained in the tests 1-6 149
70 Cross-sections of the bulbs obtained in the tests 7-9 150
X
-------
No
71 Bulb obtained in unsaturated soil [test l) 151
72 Cross-section of the bulb obtained during unconfined
grout flow (test 3)
73 Bulb obtained during confined grout flow (test 7) 154
74 Cross-sections of the rings obtained in the tests 10-15 157
75 Cross-sections of the rings obtained in the tests 16-21 158
76 Cross-section of the ring obtained during unconfined
grout flow (test 12) 161
77 Ring obtained during confined grout flow (test 17) 162
78 Ring obtained during confined grout flow (test 17) 163
79 Ring obtained during confined grout flow (test 20) 164
80 Cross-sections of the horizontal plates obtained
in the tests 22-27 167
81 Cross-sections of the horizontal plates obtained
in the tests 28-29 168
82 Horizontal plate obtained in the test 28 172
83 Horizontal plate obtained in the test 28 173
84 Horizontal plate obtained in the test 29 174
85 Vibrohammering the injection well 176
86 Jetting the injection well 176
87 Surface sealing for the grouting in unsaturated
soils 177
88 Set 1 of the grouting equipment 180
89 Set 2 of the grouting equipment 180
90 Cross-section of the bulb injected in unsaturated
soil (tests Tl - T3) 182
91 The bulb injected in unsaturated soil.(tests Tl - T3) 183
92 Cross-section of the bulb injected in unsaturated
soil (test T4) 184
93 The bulb injected in unsaturated soil (test T4) 185
94 Cross-section of the ring injected in unsaturated
soil (test T5) 186
XI
-------
Np Page
95 The ring injected in unsaturated soil (test T5J 187
96 Cross-section of the ring injected in unsaturated
soil (test T15) 188
97 The ring injected in unsaturated soil (test T15J 189
98 Location of the blocks in vertical curtain 191
99 Cross-section of the vertical curtain 192
100 A part of the vertical curtain (tests T6 - T14J 193
101 A part of the vertical curtain (tests T10, T15, T16) 194
102 Scheme of the basin 195
103 Cross-section of the blocks obtained in the tests
T17 - T20 vibrohammered injection well 197
104 Cross-section of the blocks obtained in the tests
T 21 - T28 the jetted injection well 198
XII
-------
TABLES
No Pag
1 Relative costs of chemical grouts 8
2 Properties of some UF resins applied to grouting 9
3 The influence of the temperature at which the first
period of addition reaction of F to U is carried out
on the stability of the obtained resins 13
4 Stability of SP unmodified and modified UF resins
of different molar ratios F :U (resin density =
= 1. 200 -+- 1, 170 g/cm3 dry residue 40+ 48 percent)' 17
5 Properties of SP modified resins obtained in semi-
technical scale 18
6 Properties of SP modified resins obtained in techni-
cal scale 19
7 Results of the elementary analysis of the hardened
UF resin samples modified by SP of the molar ratio
F:U:SP = 2, 1:1:0, 049 (the resin was hardened in the
solution by 30 percent hydrochloric acid at pH 2) 20
8 The values of the angle of boundary for the phases
resin UF - quartz - air (resin concentration 40 percent
viscosity 14 cP, temperature 293 K) 21
9 The properties of UF resins obtained at the molar
ratio F:U = 2, l-*-4:l 23
1 0 The properties of the resins modified by SP obtained
in the laboratory 27
11 Composition of the resin solutions hardened by hydro-
chloric acid buffered with monobasic ammonium
phosphorat and gelling times obtained at temp. 293°K 33
12 Properties of UF resins modified by addition of
different quantities of SP 43
13 Influence of plasticization of SP - modified UF resins
by means of EG on the compressive strength and the
coefficient of permeability of soils stabilized by them 48
14 Influence of plasticization of SP - modified UF resins
by means of DEG on the compressive strength of soils
stabilized by them 49
XIII
-------
No £^
15 Influence of plasticization of SP - modified UF
resins by means of FA on the compressive
strength and the coefficient of permeability
of soils stabilized by them 51
16 Influence of plasticization of SP - modified UF
resin by means of CL on.the compressive strength
and the coefficient of permeability of soils stabi-
lized by them 52
17 Influence of AA addition to SP - modified UF
resins on the compressive strength and the
coefficient of permeability of soils stabilized
by them 53
18 Mean results of elementary analysis of UF
resin extracted by distilled water and 0.1 n. HCL 65
19 Mean uniaxial compressive strength of sand samples
stabilized by UF resins stored in solutions of 66
pH 2,0 -.- 0, 05
20 Mean uniaxial compressive strength of sand samples
stabilized by UF resin stored in solutions of acids
and natrium salts 69
21 Mean results of elementary analysis of samples
of resin stabilizing soils and the values: F:U, K.
and K computed on these grounds 77
22 Estimated concentration of free formaldehyde
and pH in soil samples stabilized under field
conditions 79
23 The influence of various molar ratios F/A on the
changes of AF resin gelling times 83
24 Composition of FF grout 94
25 Compositions of grouts 145
26 Results of laboratory investigations - bulbs
Types of models: A - unwatered soil; B - watered
soil, unconfined flow; C - watered soil, confined
flow ; D - watered and stratified soil, unconfined
flow 146
XIV
-------
No page
27 Dimensions of bulbs 14?
28 Comparative coefficients of injection times
and bulbs dimensions 148
29 Results of laboratory investigations - rings 155
30 Dimensions of rings 156
31 Comparative coefficients of injection times
and rings dimensions 160
32 Results of laboratory investigations - horizontal
plates 166
33 Dimensions of horizontal plates 169
34 Comparative coefficients of dimensions
of horizontal plates 170
35 Results of field investigations - bulbs and
vertical curtain 181
36 Results of field investigations - basin 196
XV
-------
LIST OF SYMBOLS
Symbol Definition Unit
C Estimation of free formaldehyde %
concentration in sample
C,-.— Determined concentration of free %
FE
formaldehyde in extract
2
D diffusion coefficient m • 3
-1
D shear speed s
r v
2
F surface of sample cross-section m
H. head of grouting pressure measured m
as grout column above ground surface
H head of water or dilating liquid pressure m
measured as liquid column above ground
surface
I~L height of petrified block cm
h r distribution of piezometric pressures m
H difference between grout level in the m
feeding tank and groundwater level
or in case of unwatered medium -
level bottom filter injection well.
m
H. grouting pressure measured as the
difference of piezometric level
in the feeding tank and ground -
water level /expressed as the
height of water column/
H water or dilating liquid pressure m
measured as the difference
of piezometric level in the feeding
tank and groundwater level /expressed
as the height of water column/
XVI
-------
Symbol
Definition
Unit
K,
k
k
w
L
n
m
m
I
N
Nl
n
n
n
Q
Q
Q
hydraulic gradient
coefficient characterizing number
of methylol groups in hardened
resins MF
coefficient characterizing number
of methylene bonds in 'hardened ^esin
MF
grout permeability coefficient
water, permeability coefficient
lenght of injection well filter
filter elevation below ground surface
thickness of aquifer
sample mass
number of time steps
number of time step in which
displacement starts
effective porosity of soil
number of gram - molecule
of substances
temperature coefficient of resin
gelling time
injection rate
mean injection rate
m/s, cm/s
m/s, cm/s
m, cm
m, cm
G
o
initial injection rate
3/
m /s
3/
m /s
3,
m /s
XVII
-------
Symbol
Qw
q
q
R
r
r
o
rB
/
rc
T
t
t
c
t
g
t.
i
t'.
t
w
A t
V
VB
Definition
water pumping rate
injection rate per filter length
unit
mean injection rate per filter
length unit
radius of permeable area
radius
radius of injection well filter
measured range of petrified block
computed range of petrified block
measured range of the ring
interior
soil temperature
time
time of dilation
time of gelation
measured injection time
computed injection time
time of water pumping
time step
grout volume
measured volume of petrified block
Unit
3/
m /s
2/
cm /s
cm /s
m, cm
m
cm
m, cm
m, cm
m, cm
°K
s
h;
h/
h/
h,'
h/
s
3
cm
3
cm
XVIII
-------
Symbol Definition Unit
3
i
3
V .p. computed volume of petrified block cm
B
V measured volume of the ring cm
c ...
interior
3
V computed volume of the ring cm
interior
3
V water volume cm
w
3
V increase of grout volume cm
2
v volume of pumped grout per unit m
of filter length
2
v volume of pumped water per unit m
W of filter length
v velocity of flow in boundary m/s
of zones covered by grout and
water
2
v increase of pumped grout per m
filter length unit
W water content in sample of stabilized %
soil
/~i
f density of grout
cm
XX viscosity of grout cP
viscosity of grout at the grouting cP
start moment
,1 \ viscosity of grout of the grouting
'^ '' finish moment cp
,. viscosity of water cP
XIX
-------
Symbol Definition Unit
, , ..
shear stress ~~~2
m
ToC carbon content in hardened resin MF %
% Cp carbon content in methylol and %
methylene groups of hardened
resin MF
-------
A CKNOWLEDG EMENTS
In connection with the completion of project PR-5-532-6 entitled "Techni-
ques for Constructing Underground Barriers by Injection of Plastics"
I express my deep appreciation to my collaborators of the research and
the co-authors of the final report : M.Sc. engineers: Andrzej Balcerzak,
Witold Gizynski, Marek Gnatowski, Andrzej Pietak, Andrzej Wita. In addi-
tion I express my deep gratitude to dr William C.Galegar, Director
RSKERL, the project officer of this project for the assistance and kind
cooperation in the realization of the project, to Mr. Leslie G . Me Million
for the initiation of this project, and to Mr. Thomas Le Pine for his aid in the
work organization and for the pleasant atmosphere to which he contributed
a great deal, while the Polish and American parties were cooperating.
XXI
-------
SECTION I
INTRODUCTION
Protection of underground waters is one of the most important elements of
environmental protection. Since the movement of underground waters is ex-
tremely slow, pollution may be revealed only many years later . As opposed
to surface waters, the cleaning of underground waters is difficult, and in
many cases impossible. Frequently, the pollution of underground water
resources becomes an irreversible process . The quality of underground wa-
ters also determines the quality of surface waters, as many of the water co-
urses are supplied mainly by underground waters .
Industry and agriculture contribute noxious compounds into the subsoil, ad-
jacent to underground waters . When the quantity of these compounds is li-
mited, the deterioration of water quality may be contained within admissible
limits. Unfortunately, the waste disposal practices are creating more and
more cases of pollution of underground waters to the extent that they become
useless for satisfying many needs. Pollution of underground waters may
occur in large areas, as in cases of excessive application of fertilizers and
chemicals for pliant protection; or it may be localized, for example, in the
areas of industrial and communal waste disposal^ pipe leakage. In certain
•instances when penetration of the pollutants into the soil cannot be prevented,
one should attempt limiting the polluted area and protecting the unpolluted
ones. This can be done by closing the water-bearing strata with vertical and
horizontal impermeable curtains . The contaminated area can be surrounded
by a leak-proof barrier, thus interrupting the hydraulic contact with the
adjacent areas. In some cases, unclosed barriers can be constructed, which
separates the streams of underground waters .
Depending upon the soil type and aquifer depth, various methods for cons-
truction of the barriers are possible . One of them consists of establishing
walls by means of grouting. When the aquifer is very deep, a leak-proof wer-
tical or horizontal barrier may only be built by grouting .
The purpose of this study was to develop technology to construct subsurface
barriers using modified urea-formaldehyde and acetone-formaldehyde resins
in acid, neutral and alkaline soils . The resins were selected because of
their expected low production cost and availability in Poland .
-------
SECTION II
SUMMARY
Optimum conditions were attempted for the synthesis of urea-formaldehyde
resins for the purpose of soil stabilization. Methods for modification of
resins by pyros,ulphate of sodium as well as ways of hardening them by me-
ans of salt and acid solutions have been evaluated. Investigations were
carried out on laboratory, semi-technical and technical scale, for the
production of the various types of grouts . The properties of the resins as
strength and permeability of the soils stabilized by resins have been stu-
died . Investigation of plasticizers, ethylene, diethylene, furfural alcohol,
acrylic amide, and E-caprolactan, used with the modified resins have
been conducted.
Urea-formaldehyde resin is usable only for acid and neutral soils . Acetone-
formaldehyde resins were used for the stabilization of alkaline soils . The
optimum conditions for the synthesis of acetone-formaldehyde resins were
found and their properties have been determined . Catalysts for the regula-
tion of the hardening time have been selected .
Laboratory investigations consisted of obtaining different shapes of the
stabilized soil blocks by means of grouting from one grouting well. Investi-
gations were accomplished on soil models in a modeling station prepared
specifically for this purpose. The three basic types of stabilized blocks
investigated were : (l) bulb/pile; (2) ring; and (3) horizontal plate.
Laboratory experiments were conducted in unwatered and watered soils
under conditions of unconfined and confined flows . A total of 29 successful
experiments were carried out. During the experiments, the quantity of the
pumped grout as well as pressure and pumping time were measured .Grou-
ting time and dimensions of the stabilized blocks were compared with
the respective magnitudes computed theoretically.'
Field investigations were conducted on a field site in the vicinity of a
river reservoir. There were 34 experiments consisting of 16 in unsatu-
rated soil and 18 in the saturated soil. Eleven 11 piles were formed
in the vertical curtain., 18 bulbs have been joined together making one
monolithic wall. The height of the piles-bulbs varied from 1 to 4 meters
-------
and the diameter from 0.8 to 1.6 meters . Quantities of grout, injection
pressures and pumping times were measured. Test results were compared
with computed results.
Research on the process of aging the soil stabilized with resins has been
attempted . The changes of strength and permeability with time of the stabi-
lized soils samples stored in water and the air have been determined . The
investigation of the process of aging was limited to one year only. For the
purpose of long-term prognosis, and attempt has been undertaken-to explain
the mechanism of aging and to determine the factors affecting this process .
Tests have been made on the stabilized soil samples in the laboratory as
well as on the samples taken from the objects constructed in the field.
A mathematical model has been described for the penetration process of
the grout, considered as Newtonian fluid with a viscosity changeable in
time. The analytical solutions have been designed for the model and prog-
rams have been constructed for the digital computer . The three basic
patterns of the grouting investigated are: (l) viscosity of the grout diffe-
rent from water viscosity but constant up to the moment of gelation;
(2j viscosity of the grout changeable in time but constant in space; and (3)
viscosity of the grout changeable in time and in space. The presented so-
lutions are adjusted for utilization by determining the method of the grou-
ting .
-------
SECTION III
CONCLUSIONS
1 . Modified urea-formaldehyde and acetone-formaldehyde resins can be used
as grouts to seal and stabilize soils. They are characterized by having
total solubility in water in the concentration ranges investigated, forming
a pre-jelling solution of low viscosity. Polymerization occurring within
the resin-water-soil mixtures produced a strengthened impermeable
barrier having a durability exceeding twelve (l2j months.
2. Plasticizers of ethylene, acethylene glycols, furfural alcohols and acry-
lic amide did not improve grouting properties of the resins tested .
3. Gelation time could be regulated between a few minutes and tens of hours
with modification developed in this investigation.
4. Soils stabilized by urea-formaldehyde resins were found to be resistant
to deterioration over the period studied . When weakening of the structure
occured, it was caused primarily by hydrolysis of the polymer. Hydro-
lysis of the polymer was dependent upon the pH of the medium and diffu-
sion of reaction products away from the polymer site .
5. Strengths of the stabilized soils to shearing ranged from very small to
150 kilograms per square centimeter depending on composition of the
grout.
6. Variables affecting the grouting process were determine to be permeabi-
lity and porosity of the soil; viscosity of the resin solution; control of the
jelling solution; temperature of resin solution, air and soil; pH of the
resins medium and soil saturation.
7. Geometric shapes in the form of bulbs, piles, rings and horizontal plates
can be constructed in a predetermined manner and by minimal earth
displacement to provide subsurface barriers to fluid flow.
8. Mathematical models can and have been presented for the grouting process
to determine pressure and pumping times' for the grout to achieve prede-
termined geometric structures by the resins studied .
-------
SECTION IV
RECOMMEND A TIONS
1 . Additional research is required to perfect the technique of implanting
the subsurface structure to provide strengthened impermeable barriers
to fluid flows .
2. Further development of grouts with low viscosity and controlled har-
dening time is needed .
3 . The consideration should be given to exothermic effects arising in large
grout loads. In order to minimize this effect a most appropriate in-
jection technology should be developed, using grouts of selected com-
ponents .
4. Long term research on grout aging under field conditions is required.
5 . It is recommended to investigate the changes in ground water quality
resulting from the use of grouts .
6. Economic analysis should be developed to enable comparison of the
application of this technique with other presently utilized technology.
7 . Subsequent to satisfactory development of the grouting process for
various subsurface soil conditions, it should be tested on a suitable
number of existing situations requiring control by use of this of barrier
system .
-------
SECTION V
REVIEW OF LITERATURE
APPLICATION OF CHEMICAL GROUTS
Sealing and strengthening of soils by means of chemical grouts plays an
important role in civil engineering, mining work and in protection of the
natural environment. In Poland attempts have been made to apply this
method to sealing of storage yards of refinery wastes , pipelines, canals
and reservoirs ' ' .
Cementation is the oldest grouting method. However, cement leaves solids
suspended in water which have a limited penetration capability in porous
media. Flow of the cement grout may only take place if the capillary dia-
meter is 4-5 times bigger than that of the cement solids. Application of
Portland cement is limited to soils with a coefficient of permeability of
80-200 m per 24 hours5 • 6.
With soils of lower permeabilities it is necessary to apply solutions of
emulsions of binding compounds . The following compounds are currently
the most frequently used:
- sodium silicate (liquid glass)
- acryloamide and its derivatives,
- amino-and amido-formaldehyde resins,
- phenol-formaldehyde resins,
- lignosulphonates,
- furfuran polymers,
- acetone-formaldehyde resins .
289
The range of application of some grouts is given in Fig. 1 ' ' . The speci-
fied chemical grouts are, however, relatively expensive. Prices of some
of the applied grouts are presented in Table 1 ' .
-------
GRAVEL
1
FINE
SAND
1
COARSE
| |
MEDIUM
FINE
CLAY SOIL
COARSE
SILT
SILT
(NON - PLASTIC)
ACRYL POLYMERS
(AM -9. PWG)
LIGNOCHROMICS
11
.
n
L
1
UREA -FOE MA!
(HERCI
! !
Ml
PHENC
L
L
J
)]
L
E
L
L
L
1.
>E1
,01
Lt
TYE
<)
E
~~
RESINS
|
I
-FORMALDEHYDE RESINS
SILICATE
(iNJECTROL G)
CEMENT
X
10 0
1 .0
0.1
0.01
0.001
Fig.l Soil limits for grout injectivity
;rain size in mm
-------
TABLE 1. RELATIVE COSTS OF CHEMICAL GROUTS
1
No
1 .
2.
3.
4 .
5.
6.
7 .
8.
Chemical grout .
Cement grout (d = 1 .5 unit/m )
Liquid glass with calcium
chloride according to Joosten
Acryl polymers (AM-9J
Resorcin - formaldehyde
resins
Lignosulphonates with sodium
dichromate
UF resins
Bituminous emulsions
Epoxy and polyester resins
— _— _ __. _ __
Cost
in capitalist
countries
1 .0
2.5
2.4 - 9.5
,2.4 - 9.5
1 .5
3 4
1.5-6
36 - 120
index
in Poland
1 .0
_
-
1.5-4
6 - 8
6
80
Relatively high prices of organic grouts limit their application. It should be
expected, however, that large volume manufacturing will decrease costs of
organic grouts. With this in mind, investigations were initiated relating to
soil stabilization by means of organic grouts . With attention given to a cheap
raw material available in Poland, the range of application and properties.,
the following promising grouts were selected for
investigation:
urea-formaldehyde resins,
acetone -formaldehyde resins .
UREA-FORMALDEHYDE RESINS
(UF)
The first attempts to stabilize soils by means of UF resins were made in the
United States in the 1940s. Since then they have found entensive applica-
tion in grouting technologies . These compounds are particularly valuable for
grouting stabilization due to such properties as :
low viscosity,
solubility in water,
wide range of regulation of the time of transition from solution into gel,
high rate of sealing and strengthening of stabilized soils,
resistance to ageing processes and powerful media.
-------
TABLE 2. PROPERTIES OF SOME UF RESINS APPLIED TO GROUTING
No
1 .
2.
3.
4.
5 .
6.
7 .
8.
9 .
10.
_ _
Name of resin
Krepitel M4' 5 ' 6' ? ' 11
MF - 1711'15"
M - 6012
MFS - 713
14
MFF
R 1 R
MM - 2 '
r* 1C
Karbaniid '
lie17
Dukol7'18
3,9,19,20,21
Herculox
Country
USSR
USSR
USSR
USSR
USSR
USSR
Poland
Poland
Czech .
USA
Recommended
concentration
of 1 % 1 resin
20 - 50
30
30 - 60
60 - 70
N.A .
N.A .
30
30 - 60
30
50
_
Viscosity
(cP)
6 - 60
N.A .
N.A .
N.A .
N.A .
N.A .
6
6 - 200
10 - 15
13
—
Hardener
U - -
HC1
HC1
acids
acids
acids
acids
HC1
acids
HC1
Ammonium
salts
Compressive
strength of soil
(N/nr2) -'lO6
L - - —1
1 - 5
6
1 - 30
N.A .
N.A .
N.A .
15
10
5
13
-------
Properties of some of the UF resins applied to grouting are given in Table 2 .
Soils stabilized by UF resins reach a high rate of sealing. These resins were
applied to the surface of reservoirs5'22 and in some mining work to combat
the water hazard in mines.13'14'15'16 The coefficients of permeability
from 10"9 to 10"6 m/s4'?2 of the sealed soils depended among other factors,
on the kinds of applied resin, and the concentration and the amount. The prac-
tical water permeability of soil, treated with resin, diminished in the field
from a few dozen to a few hundred times .4j A high rate of sealing makes
it possible to use the UF resins for construction of impermeable curtains
preventing pollution of underground waters .
Soils stabilized by UF resins are considerably stronger than unstabilized soils.
Their property may be used in those cases where it is necessary not only to
seal but also to strengthen ; e.g. while constructing impermeable walls under
the foundations of structures . The strengthening effects are subject to a
number of factors which include the following; the kind and concentration of
resin, grain size composition, petrographic composition and soil density. 3
Influence of the wetting power of minerals by resin on the obtained strengthe-
ning effects was noted.
Resistance of soils stabilized by UF resins to aging processes is an important
factor determining the range of work which can be carried out by means of this
method . The available literature contains general remarks about a long-term
1 7 1 °i
durability of soils strengthened and sealed by UF resins. ' Rzhanitsin,
z4 25
Bleskina and Tshaykova have found that UF resins are resistant to
underground water pollution., particularly acid and alkalic media ranging
between pH 3-13. The mechanism of aging and factors causing aging of soils
stabilized by UF resins have not, however, been explored thoroughly. The
range of their application has as a rule been limited to neutral and acid
soils . This range may be extended by a primary washing of soils by acids .
Generally it is assumed that grouting is economically justified in soils
containing less than 3 to 5 percent of carbonates and 10 to 15 percent of
clay.i?,19,26
ACETONE-FORMALDEHYDE RESINS
AF resins are primarily for surface stabilization of soils, e.g. in road
construction or soils preparation for ore extraction27 ' 28 . Grouting stabili-
zation of soils was accomplished by means of acetone and formaldehyde
solutions hardened by alkaline catalyzers.29 Notes concerning properties
of stabilized soils, by AF resins, including strength and permeability are
rather vague . It has been stated that the soil strength of 9 . 2 -106 N/m2 ' 2?
was obtained in the case of a surface stabilization and that samples obtained
from grouting by acetone and formaldehyde are waterproof.29
10
-------
The literature lacks information concerning the range of application of AF
resins to soil stabilization. Since they are hardened in alkaline media, these
resins should supplement UF resins in this respect. Limited information
concerning AF grouts stimulated the present investigation.
11
-------
SECTION VI
SYNTHESIS OF LOW - VISCOSITY UREA FORMALDEHYDE
RESINS AND THEIR MODIFICATION BY SODIUM PYROSULPHITE
AND PROPERTIES OF STABILIZED SOILS
Urea-formaldehyde resins (UF resins) have been used for grouting soil
stabilization of thirty years . In many cases, better sealing was achieved
by use of modified resins for this purpose. Among many possible modifica-
tions, condensations of resins with sodium pyrosulphite (SPJ deserves
notice . On the basis of the literature inquiry we can not find that they have
been used as chemical grouts .
An introduction of sulfonate groups into the structure of cross-linked resins
should reduce the effect of the syneresis occuring during hardening and
should consequently improve sealing capacity of the chemical grouts . It is
especially important in the case when the resin is used for the production
of impermeable curtains in the soil. On the other hand, hydrophilic proper-
ties of resin molecules should also advantageously influence the process
of polycondensation connected with formation of cross-linked polymer, espe-
cially in dilute solutions.
Synthesis of the resins modified by SP does not differ much from the gene-
rally known methods of obtaining UF resins . In the investigations reported
in the present paper, a two stage method of resin 3 ^j^o Syn-tiiesis was
accepted as the production method.
Molar ratio of formaldehyde (F) and urea (u) reagents = 2.2:1 was accepted
as an optimum one because the resins of this approximate molar ratio assu-
res high endurance properties and impermeability to the stabilized soils
as confirmed in later works . However , industrially obtained UF resins of
such molar ratio possess comparatively high viscosity (about 50cP at 293°]
and can precipitate collodial deposit which makes grouting in silty soils
difficult.
To investigate the synthesis of low-viscosity UF resins ^viscosity below
25cP at 293°K with 45 percent of fixed substances) , which would make
12
-------
an ideal solution, the structure of the precipitating deposit was investigated.
Collodial deposits were isolated from the resins obtained in the laboratory
by the two stage method having a molar ratio F:U =2.1:1. It was washed
with a 3 percent solution (concentration approximate to the content of F in
the resin) and next washed with distilled water, and vacuum dried at a
temperature 308° + 2°K. Its infra red spectrum (iR spectrum) of the subs-
tance was obtained and compared with the IR spectrum of the washed sample
of the cross-linked UF resin of the molar ratio F : U = 2 .1 : 1 . The collodial
deposit had a structure similar to the cross-linked resins (See Figure 2) .
The UF resins formation at the chemical equilibrum state is highly depen-
dent on the coii-litions of the synthesis . In the initial period of the reaction,
F unites with U in an environment approximate to the neutral one (pH 7.5-
6.5) . Velocity of an undesirable reaction of condensation can also occur
depending on the pHj temperature , environment, and degree of U substitu-
tion '. Reduction of the value of pH accelerates the reaction between
oh oo
methylol and amide or amino groups ' . This change can occur in the
reaction mixture due to Cannizzaro's reaction. An increase of temperature
causes the shift of the reaction equilibrium towards the formation of inter-
molecular bonds accompanied by decreased number of methylol groups 3°°t
Velocity of the intermolecular bonds formation is also reduced when the substi-
tution of U molecules in F solution increases . So formation of these bonds
occur at the largest velocity in the first period of reaction.
A series of resin syntheses was performed during which the process of addition
F : U (the first period of synthesis) was done within 45 minutes at the tempe-
ratures 293° - 2°K and 353° * 2°K and then completed at boiling conditions
(367 K) within 30 minutes . The initial value of pH reaction mixture, after
being treated by 3 percent sodium hydroxide, was 7.5. A majority of the mo-
nomers were found to react at the temperature of 318°K within 45 minutes.
This was evidenced by the strongly exothermic effect of the reaction which
lessened after 30 minutes . When the process of condensation was accomplished
in the boiling conditions at pH 4.6 - 0.2, the resins of designed viscosity were
neutralized and cooled. The properties of the obtained resins are oiven in the
table 3 .
13
-------
1800
1400
1000
warelength
Fig . 2 IR spectrum of colliodal deposit isolated from UF
resin (l) and hardened UF resin (2j
1800 1400 "1000"
warelength
Fig . 3 IR spectrum of hardened UF resin (l) and UF
resin modified by SP
14
-------
TABLE 3. THE INFLUENCE OF THE TEMPERATURE AT WHICH - THE
FIRST PERIOD OF ADDITION REACTION OF F TO U IS
CARRIED OUT ON THE STABILITY OF THE OBTAINED
RESINS
1 -
Tempe-
rature
I K'
293 - 2
318 - 2
318 - 2
353 - 3
318 - 2
Molar
ratio
F:U:SP
...
2.1:1:0
2 .1:1:0
2.1:1:0
2.1:1:0
2.1:1:
0,049
Time of
addition
reaction
at decre-
ased
temp .
(min .)
_____
45
45
90
45
45
Resin
visco-
sity
at 293°K
(cP)
23- 1
34- 1
23-1
22* 1
25 - 1
t _ — - -
Resin
density
at 293°K
(g/cm3)
. .
1 .175
1.175
1.175
1.175
1 .195
X
Dry
residue
(*)
44
44
45
44
46
XX
Resin
stabi-
lity
-~ to —
till 1
hour
about 3
days
about 3
days
till 1
hour
about 3
days
See method for explanation
xx Time when first sediment noted
It is clear from the achieved results, (the resins of the largest stability without
turbidity and deposit ) are the ones obtained in the synthesis which F and U
o o
were added at 318 K. Decrease of the temperature of this reaction to 293 K
was deemed flot to be advisable as it crystalized the methylol ureas . On the
other hand, an increase of temperature up to 353 K worsens stability depen-
ding on the quantity of formed methylene ureas . It was concluded that the
changes of temperature accordingly influenced the pH of the reaction mixture
(attU8°KpH diminished from 7.5 to 7.0-7.2 and at 353°K pH diminishes
from 7.5 to 6. 5-6.3 J. The period of the reaction, when prolonged at the low
temperature (318 K), does not improve resin stability (Table 3) .
Due to observed tendency of the resins obtained at molar ratio F:U = 2.1:1 to
cloud and precipitate deposit, the influence of the molar ratio F:U= 2.5:1
on the resins stability was investigated . A series of syntheses was also made
for the following molar ratios: F:U = 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1.
15
-------
The resins were synthesized by the two stage method with a low temperature
period of F and U addition being preserved. During condensation in boiling-
conditions at pH 4.7-0.2, the samples of the following viscosity were Q N
taken from the reactor: 8 - 9.5cP s 10 - IcP, 15 - IcP, 19 - 2cP (at 293 K;
They were neutralized by 3 percent NaOH to pH 7.0:7.5 and were under
observation for 90 days (Table 4) . The test did not cover the molar ratios
of reactants above 2.5:1 as the molar ratio of F:ll=2.1:l was later
indicated to be optimum from the point of view of the strength of the soil
samples. Through condensation of resins containing more F, it is possible
to obtain an optimum ratio of the reactants by dissolving an adequate quan-
tity of U in the resins or in the hardener . Samples of the stabilized soil are
found to be less strong, the more U is dissolved in the resins . The molar
ratio of F:U can affect the resins stability because chemical equilibrium
is shifted toward formation of methylol ureas . At the same time methylene
ether bonds are formed instead of the competitive methylene ones . The
stable resins of lower viscosity were found to be obtained when the molar
ratio F:U increased. For example : At the molar ratio F:U 2.5:1 the stable
resin of 9cP viscosity (at 293 K) was obtained, while viscosity of the
reaction mixture before condensation was equal to 7cP (at 239 Kj .
When stable low-viscosity UF resins were obtained,, the synthesis of UF
resins modified by SP was randomly investigated . After the introductory
tests the maximum molar ratio F:U:SP= 2.1:0.049 was accepted because
the resins containing more S? (F:U:SP = 2 .1:1:0 .09y hardened insuffi-
ciently and the samples of the soil stabilized by these resins were destro-
yed when stored under water .
Modified resins were obtained in the same way as unmodified ones. Si5 \\\-..;
introducted to the reaction by being dissolved in formalin with U (pH 7 .0] .
The solution usually required acidification before synthesis . Results of
the syntheses are shown in Table 3 and 4. It was concluded that SP modi-
fication did not influence in a perceptible way the stability of the resins.
These results led to the determination of the optimum conditions for the
synthesis of stable,, low-viscosity UF resins modified by SP . From the
point of view of stability., the molar ratio F:U =2.5:1 was accepted as the
most profitable one . When urea and sodium pyrosulphite were dissolves
in formalin, the solution was neutralized to pH = 7.5 and then heated
at. 318 K for 45 minutes, continued in boiling conditions for an additional
30 minutes and later acidified by 3 percent HC1 to pH 4.7:0.2. The resins
are condensed in this boiling condition to obtain a viscosity above 9cP.
They are then neutralized to pH 7 .0 to 8 .0 and cooled to room temperature
16
-------
TABLE 4. STABILITY OF SP UNMODIFIED AND MODIFIED UF RESINS
OF DIFFERENT MOLAR RATIOS F:U (resin density = 1,200*
l,170g/cm , dry residue 40^48%
~
Molar
ratio
F:U
2,1:1
2,2:1
2,3:1
---___«
2,4:1
2,5:1
Viscosity
at 293°K
(cP)
8 -0^5
10 ±1
i _ -.
15 ±1
19-2
8 -0,5
10 ±1
15 ±1
19- 2
|__ __._
8 - 0,5
10 + 1
15 ±1
19-2
8 -0,5
10 ±1
15 - 1
19-2
a
8 -0,5
10 ±1
15 ti
19-2
Unmodified
resin
!! Molar ratio F : SP |
1:0,00143 j 1:0,0233 j
i
Ageing period in days i
1 f 3
-
-
+
+
-
+
+
-
+
+
-
+
-t-
+
+
+
+
+
1
+
i_ _
L
1
+
H ~
+
I
+
1
+
L'_ _
+
4-
+
+
7 ! 14 ^28
, . _ L _
1 I
I 1
I }
I '
,- 1
1 '
i i
_
I '
I 1
1 l
L _1 L
i '
i '
J '
J_ r _.
l l
l '
l | t- —
i + ' +
+ i - ' -
1 | _ !
1 '
1 '
1 '
-- -[ - -r - 1
l '
i i
i. _j i _
90J! 1
t _,
ii
u -
ii
ii -
it"
,! H-
" ~ TI " -
-!! +
1!
II -
M
II
II -
II
~ - TI
11 +
il
_ -H
II
-" ij.+ -
II
II
II
- TI
II
II ~
11
+i i 'II
I i - ' - ' - II +
l ' > '1 +
i + ' +
+ l - ' -
, _ _i_ i
l '
I '
i >
s r ">
1 '
1 I
1 *~ "*
, + . +
+ , - 1 -
t L. -J
1 1
+ 1 + ' +
_ L ' -
1 '
] L
i '
__+_l_tll..
i '
__t;_t_i.+_.
i r
+ ', + ! +
TI
+ II
- II +
JJ 1
II
II _
II
~ "TI ~-
II +
II "
n — i
- ii +
ii
+ !! +
lit
_ u
n
+ " +
. _ 11 _ _ _
n
+ .! +
H
ii
-c n +
3 i 7
i .
i
i
i
i
i
~* i
+ i -
~r \
\
i
i
i
- " r
_ i
+ L.+.J
i
i
143 28 i 90l 1 i 3 ! 7
^ L. —1 L 1
+
+
_
i i
1 !
L J
t 1 i
i
i
+ ' +
i
i
i
i — i
i
- i
i
+ i +
i
+ ; +
i
i
i
!
+ ! +
+ : +
i
i
+ i +
-
+
+
+
+
4.
+
r —
+
+
—
+
+
+
+
+
-
-
-
+
+
+
+
+
+
i i
- i i
1 U J
+
+
+
+
-
-
+
+
-
+
+
+
-
+
+
+
1
1
1
- 1
+ i'
1
1
1
1
1
1
_ 1
1
, _ —
1
+ > +
_4 —
1
_ ^
1
1
+ ! t
i
— i —
i
+ i +
i
i
i
~i-
i
— i
i
+ J +
i
+ | +
i
i
i
~ - "
+ : +
~~ i~ ~
+ : +
14 '28 . 90 '
4. '
i '
i |
4
1
_I_
L _ _
+
-
+
+
+
i
+
+
- - - - r - -
I '
+ i + ' +
1 ,
u ,
+
\- 1
*- - 1
+
-
-
+
T
+
+
!
1
I
1
1
1
4
1
- J.
|
1
I
1
j
I
I
i
I
1
1
I
~ I
+ .'
1
1
!
i
1
1
I
+ :
i
i
~ 4. ;
i
+ i
i
+ i
+ resin without traces of cloudiness
+ resin with opalescencing clouding
- resin with precipitated deposit
17
-------
Due to the investigations concerning the soils stabilized by UF resins
modified by SP, two types of resins of the following molar ratios
F:U:SP = 2 .5:1:0 .00357 and 2.5:1:0.0583 were selected for further study
The investigations of synthesis on the technical scale and with use of
industrial apparatus (within the frame of informative production) were
carried out for these resins. This study tested resin ,-ynthesis techno-
logy using technical grade materials . It also secured a large portion
of material for aging investigations and investigations of grouting
techniques . The syntheses on a semi- technical scale and with use of
industrial apparatus, carried out according to the previously mentioned
reactors
description, showed that the course of reaction was similar in
3 *^
of capacities ranging from 0.2m to 5m . The tests also indicated
that exothermic effect of the reaction of F and U could be controlled when
heating of the reactor began at 308 K and cooling at 313 K. The resins
had small opalescencing cloudiness, probably due to the technical raw
materials contaminations, having properties as listed in Table 5 and 6.
TABLE 5 . PROPERTIES OF SP MODIFIED RESINE OBTAINED
IN SEMITECHNICAL SCALE
1
2
3
4
5
6
7
Properties
Density at 293 K in g/cm
Viscosity at 293°K in cP
pH 293°K
Dry residue , percent
Acetate tolerance
Content of free F, percent
General appearance
'
Molar ratio F : U : SP
2.5: 1 : 0.00358
1 170
10
40
total
3.7
2.5:1: 0.0584
1 193
14
7 .8
43
total
o o
o . u
colorless, limpid liquid
of slight opalescencing cloudiness
-------
TABLE 6. PROPERTIES OF SP MODIFIED RESINS OBTAINED
IN TECHNICAL SCALE
1
2
3
4
5
6
7
•
r
Properties
Density at 293°K
, o
in g/cm
Viscosity
at 293°K
in cP
pH at 293°K
Dry residue
in percent
Acetate tolerance
Content of free F
percent
G eneral
requirements
by Contempo-
rary Conditions
Molar ratio ]
2,5:1:0,00358
9430 kilo
portion 2
1 .175
16
7 .6
43 .2
total
3.8
fulfill
i
F:U:SP and batch
2.5:1:0,00358
9660 kilo
portion 2
1 .174
•11
7 .6
45 .4
total
3.2
fulfill
- - j
1
quantity
2.5:1:0,058
9660 kilo
portion 2
1 .205
11
7 .0
48 .3
total
2 .8
fulfill
i
THE STRUCTURE AND PROPERTIES OF LOW-VISCOSITY UF RESINS
MODIFIED BY SP
Investigations concerning the structure of the cross-linked UF resins modi-
fied by SP were carried out on the basis of the results obtained from the
elementary analysis and IR spectrum of the resins with molar ratio F:U:SP =
2.1:1:0.049. After 7 days the sample of the resin hardened by hydrochloric
acid solution at pH 2 was pulverized and extracted by distilled water . The
IS
-------
elementary analysis was done for an unextracted sample and the samples
analyzed after 1 montlh and 3 months of extraction (Table 1) .
TABLE 7. RESULTS OF THE ELEMENTARY ANALYSIS OF THE
HARDENED UF RESIN SAMPLES MODIFIED BY SP OF THE
MOLAR RATIO F:U:SP = 2 .1:1:0 . 049 the resin was hardened
in the solution by 30 percent hydrochloric acicl at pH 2
Period
of sample
extraction by
distilled water
unextracted
resin
1 month
3 months
Content
% N
25 04
31 .81
31 .95
of elements
% C
_ _ i
30.74
32.25
32 .41
percent
°/oS
3.07
0.85
1 .03
i _ _
Ratio of
sulphur /nitrog en
weight content
°/oS / foN
0.122
0.027
0.032
IR spectrum was made for the sample after 3 months of extraction (Figure 3
The results presented in Table 7 show that the unextracted sample contains
3.07 percent of sulphur which is approximately the estimated theoretical
quantity of 2.8 percent. Only 25 percent of the sulphur introduced to the
reaction is constantly bounded to the polymer. Occuren.ce of sulfonate
groups in modified resins is confirmed by comparison of IR spectograms
of the extracted samples of modified and unmodified resins (Figure 3j .New
bands appear for the wave lengths 1105 cm *• and 805 cm when the resins
are modified. The band on the range of 1105 cm" probably comes from
resonance vibrations of the SO? group
Wetting power of minerals is the essential property of the resins used as
chemical grouts . It expecially applies to wetting of quartz which is the
main component of the stabilized soil. Some authors maintain the resin
O O
wetting power of minerals is connected with the resin adhesion to them".
Investigations of the angle of boundary for the phases UF resins-quartz-aiv
were carried out for 40 percent solution of unmodified resins and modified
ones of molar ratio F:U:SP= 2.1:1:0.003 and 2 . 1: 1:0 . 00049 . Measurements
were taken at temperatures 293± 2°K and the results are given in Table 8.
20
-------
TABLE 8. THE VALUES OF THE ANGLE OF BOUNDARY FOR THE
PHASES RESIN UF - QUARTZ - AIR (resin concentration
40 percent, viscosity 14cP, temperature 293 K)
Type of UF resin
Average value of the
'•to
angle of boundary
Ra
unmodified resin (F:U=2.1: 1
modified resin fr : U : SP = 2 .1:1:0 .003)
modified resin (F : U : SP = 2 .1: 1:0.049
0.330
0.376
0.334
Values of the angles of boundary ranging from 0.330 Ra to 0.376 Ra, were
approximate for all investigated resins and it is clear from these experi-
ments that modification of UF resins by SP do not influence their wetting
power . So it may be assumed that adhesiveness of modified resins to
quartz, being the component of the stabilized soil, is not higher either .
The mathematical description of filtration of chemical p'routs requires
knowledge of the rheology properties of resin solutions of various viscosi-
ties . Measurements of this kind were carried out on the rotative vicometer
for shearing stresses t = 7 to 70 N/m" and shear velocity Dr =5-1000 ;
at temperature 293.0 - 0.1°K. Investigations were conducted on resin
samples of the molar ratio F:U:SP = 2.1:1:0.049 and concentration of 40
percent. Different condensation rates, having viscosities ran
-------
CM
I
6
.5, 60
w
CD
r
™ <0
cd
0)
201
Q.
^~
n
^p
200
400
oOO 800 1000
shear velocity (.S
Or
Fig. 4 Function diagrams
modified by SP
= f (Dr) for UF resin
22
-------
H"
+ HO
. .C-NH-CHOH + H N-C^v-^-^C-NH-CH -CH-C^
ii 2 2 11 ii A
O 00 O
This condensation is catalyzed by hydronium ions, the concentration of which
limits the process velocity. In the acid environment at pH 4 the velocity of
formation of methylene bonds exceeds the velocity of addition of M and U
leading to the formation of methylol groups :
C- NH,
ii
O
C - NH-CH OH
LJ
In the reaction environment, methylol groups assure solubility to the macro
molecules in the first period of hardening. The resins hardening process
occurs clue to condensation, and depends on the methylol groups not being
excessively decreased . Otherwise, low molecular hydrophobia fractions
deposit from the solution and they lower the strength properties of the
hardened resins . Hence, the structure of the polymer is determined by the
initial ratio of methylol, amide, amiiio groups and concentration of free F
occuring in the reaction mixture .
The accepted technology of increasing the solubility of U in resins obtained
at the molar ration F:U=2.1:1 is not profitable from the point of view of
its hardening mechanism. An increase in the quantity of dissolved U should
effect the polymer occuring after hardening to have more hydrophobia pro-
perties . Investigations were made of the variance of four molar ratio of
F:U on the soil stability. "Resin syntheses were made according to the pre-
viously presented description and their properties are given in Table 9.
TABLE 9. THE PROPERTIES OF UF RESINS OBTAINED AT THE MOLAR
RATIO F:U =2.1 to 4:1
Molar
ra tio
F : U
2.1:1
2.5:1
3 : 1
4 : 1
Viscosity
at
293°K
(cP)
27 .2
13.8
9.8
4.7
i
Density
at
293°K
(g/cm3)
1 .172
1.146
1.136
1.120 ;
1
Dry
residue
«
i ]
45 .6
35.0
31 .0
25 .0
pH
6.8
G.8
6 .8
7 .0
•
23
-------
The samples of the stabilised soil were made by saturation of sand with
solutions of the following composition :
resin (F:U = 2.1:1 after U being dissolved) 100 parts by volume
water 45 parts by volume
10 percent oxalic acid (to pH 2) 5 parts by volume
Solutions of U and F were also used for stabilization.
The samples were tested for resistance after 7 days storage.
Results are given in Figure 5. It was concluded that an increase of the
quantity of U dissolved in the resin is followed by a decrease of the strength
of U stabilized soil. Accepting compressive strength of the sample of the
stabilized soil as an evaluating criterion, two UF resins modified by maxi-
mum and minimum quantities of SP (F:U:SP = 2 .5:1:0 . 003 and 2.5:1:
:0.049) were made .
The following molar ratios U was dissolved in the earlier resins : F:U =
2.3:1, 2.1:1, 1.9:1, 1.7:1, 1.5:1. The solutions prepared in this way
were diluted to contain 30 percent fixed constituents and hardened by oxalic
acid solutions . Figure 6 illustrates compressive strength of the samples
of the soil stabilized by those solutions after 7 days storage under water .
It is evident that the previously accepted molar ratio F : U = 2.1 : 1 is an
optimum one which is likely to be independent of the quantity of SP within
the investigated range of molar ratio F : SP .
A portion of this-study of hardening UF resins consisted in the control of
their gelling time. The possibly wide range of gelling time control - from
a few minutes to some scores of hours is advisable in the case of grouting
resins . Short transition times of solutions into gel prevents washing out
of the chemical grout sealing the soil during the quick flow of under-ground
waters . Long transition times enable stabilization of silty soils of small
coefficient of permeability. It is indispensible to know the resin gelling
times and characteristics of viscosity changes occuring during hardening
to select grouting parameters
Gelling velocity depends on the hardening catalyzers. The review of har-
deners used for amino-plastics is given by Wirpsza . 3C? 3!^ , 36 . jn ^s s^udy
the two groups of hardeners used are acids and ammonium salts . In the
resin hardened by acids (hydrochloric, sulphuric, phosporous, oxalic)
a constant hydronium ion concentration is sought. For the present report
the investigations of velocity of acid hardening were carried out for UF
resins modified by SP at the molar ratios F : U : SP = 2.5:1:0.00357
and 2.5:1:0.0583. The properties of these resins are given in Table 1C.
24
-------
5-lQ5_
'on
c
CD
cu
w
tn
fi
o
U
2.0 :1
2.5 '
M
-------
6'10'
CM
I
QJ
f-,
-t— >
CO
(U
en
en
0)
O
U
X5'1
19'i
2J! 1 .2,3-1
molar ratio
Fig. 6 Dependence of compressive strength of soil samples
stabilized with UF resins modified by SP on molar
ratio F : U
1 F : SP = 2.1 : 0.049
2 - F : SP = 2 .1 : 0.003
26
-------
Just prior to the tests . U was dissolved in the resin in quantity to achieve
the molar ratio F:U =2.1:1. Oxalic acid, introduced as 10 percent solu-
tion, was chosen for the hardener . Measurement of gelling time were taken
at temperature 293 * 1°K for the 30 percent resin solution of the molar
ratio F:U:SP= 2.1:1:0.0.49 at pH = 2 to 0.8 and for the 30 precent resin
solution of the molar ratio F:U:SP = 2 .1:1:0.003, at pH = 2.1 to 1.0.
TABLE 10. THE PROPERTIES OF THE RESINS MODIFIED BY SP
OBTAINED IN THE LABORATORY
T
1
2
3
4
5
6
7
Properties
—
Q
Density at 293 K in g/cm
Viscosity at 293°K in cP
pH at 293°K
Dry residue %
Acetate tolerance
Content of free F %
General appearance
Molar ratio F : U : SP
2.5:1:0.0583
1 .171
14
6.8 - 7.0
42
total
3.6
2.5:1:0.0584
1 .850
14
6.8 - 7.0
45
total
3.1
colorless, limpid, liquid
PH range was restricted by the solubility of oxalic acid and by the influence
of pH 2 on the gelling velocity of the solutions . The obtained results of
gelling time are given in Figure 7 . It was concluded that the use of acids
at pH 2 to 1 enables control of gelling time of resins within the range of
6-40 minutes (at temperature 293 K) . In the case of the resin with molar
ratio F:U:SP = 2.1:1:0.049, a longer gelling time was observed in compari-
son to the resin of the molar ratio F:U:SP = 2 .1:1:0 .003 . This effect is
probably connected with modofication of resin by SP . To achieve longer gel-
ling times investigations concerning control of velocity of resin hardening
by catalyzers like ammonium salts were also conducted. Solutions used for
the investigations were the same as in the case of hardening by oxalic acid .
Ammonium chloride was used as a hardener introduced in the form of 25
percent water solution in quantities amounting to 5 ml to 50 ml of 25 per-
cent NH4C1 in 100ml of 45 percent resin solution. Measurement tempera-
ture was 297 ± 1°K. The results given in Figures 8 and 9 showed gelling
times ranging from 60 minutes to 100 minutes for the resin of molar ratio
F:U:SP = 2 .1:1:0.003 and for the resins of molar ratio F:U:SP = 2.1:1:0.049 .
27
-------
Q8 a9 1.0 1.1 1.2 1.3 1.4 1.5 V6 1.7 1.6 1.9 2.0 2.1 2.2 2.3
pH
Fig .7 Influence of pH on gelling time of 30% UF resin solution
modified by SP hardened with oxalic acid
1 - F :U:SP = 2.1 : 1 : 0.003
2 - F : U:SP = 2.1; 1 : 0.049
28
-------
0>
0)
bo
IvJUU
1320
1260
1200
1140
1080
1020
960
900
B40
/i8G j
4?n
360 .
300 .
240
180
120 .
6U
1
5
4'
3
^
2 ,
1 \
>
i
5
! \
! V
I
\
\
^ \j
rV^**--
X^
V
)
V.
^
£
^
^
.^
(
6
^v^.^
i
)
f
zg*;
i
i
"K
i
)
C
>
>
10 2Q 30 40 50
ml 25% NH4C1/100 ml of resin
Fig.8 Gelling times of 30% UF resins (F:U:SP=2 .1:1:0 .003)
hardened with ammonium chloride (l) and ammonium
chloride buffered with hexamethylenetetramine
(urotropin) in quantities : 0,5g (2) , l,0g (3) ,
2 , 0 g (4) , 3 , 0 g (s) , 4 , 0 g © , per 100" ml of
resin
29
-------
ml 25% NH4C1/100 ml of resin
Fig. 9 Gelling times of 30% UF resin solution (F:U:SP =
2.1:1:0.049) hardened with ammonium chloride (l)
+ ammonium chloride buffered with hexamethylene-
tetramine (urotropin) in quantities : 0.5g (2) ,
l,0g (3) , 2,0g (4) , 3,0g (5) -, 4,0g (6) , per 100 ml
of resin
30
-------
1440
CO
o>
r-H
i—I
-------
to
ID
OJ
o
1680 J
1620
•S 1560
JL
(500
1440
1380
1320
2Q7°K
60
30 40
ml 25$ NH4C1/100 ml of resin
50
Fig.11 Gelling times of 30$ UF re'sin solution (F:U:SP =
=2 .1:1:0 .049J hardened with ammonium chloride
buffered with thriethylenetetramine (TETA)
in quantities: 0.5 ml (l) , 1 ml (2) ,1,5 ml (3)
2 ml (4) , 2,5 ml (5) , per 100 ml of resin
32
-------
They only slightly depend on the quantity of the introduced ammonium chlo-
ride . Gelling time for the resins of the molar ratio F:U:SP = 2 .1:1:0 .049
is found to be longer as it is in the case of the acids . A wide range of control
of gelling time up to 24 hours at temperature 297 K, was possible to obtain
by an additional introduction of hexamethylene tetramine in the quantity
of 0.5 to 4.0 gram per 100 ml of 45 percent resin and triethylene-tetramine
in the quantity of 0.5 to 2.5 ml in 400 ml of 45 percent resin to the resin
sample hardened by ammonium chloride (Figures 10 and ll) . Larger
amounts of amines makes precise determination of gelling times difficult.
The use of the hardener in the form of hydrochloric acid buffered with mo-
nobasic ammonium phosphate was investigated for the previously utilized
resins of the molar ratio F:U:SP = 2 .5:1:0 .00357 and 2 .5:1:0 . 0583 . Measure-
ments were taken at temperature 293°F -IK. To achieve the molar
ratio F:U= 2 .1:1, U was dissolved in the resin before measurements. Com-
position of the investigated solutions and the obtained gelling times are
given in Table 11 .
TABLE 11.
COMPOSITION OF THE RESIN SOLUTIONS HARDENED
BY HYDROCHLORIC ACID BUFFERED WITH MONO-
AMMONIUM PHOSPHATE AND GELLING TIMES
OBTAINED AT TEMPERATURE 293°K.
Molar
ratio of
reagents
in resin
F:U:SP
2,1:1:0,003
_
2,1:1:0,049
'
_
NH4H2P04
(g)
2
2
2
2
2
2
2
2
1
1
1
HC1
36%
(ml)
0.5
0.4
0.3
0.2
0.1
0.5
1 .0
2
0.5
1
t-\
Water
(ml)
7.7
7 .8
7.9
8.0
8.1
7 .7
7.2
0.2
8.6
8.1
7.1
1
resin
(ml)
20
20
20
20
20
20
20
20
20
20
20
initial
PH
(pH)
-,
2.6
2 .5
3.1
3.5
3.9
2.5
1 .8
0.9
-
gelling
time
(min)
56
76
111
127
187
_ ~ ~ ~1
145
37
7
85
15
3
>_
33
-------
ra
0)
a
OJ
303
298
293
288
283 .
300 360 «20
gelling time (min)
Fig .12 The influence of UF resin (F:U:SP = 2,1:1:0,003) hardened
with oxalic acid (l) , hydrochloric acid buffered with
monobasic ammonium phosphate (2) and ammonium
chloride (3j on gelling times
34
-------
303,
296._
n)
f-,
a 2Q3
6
0) .
H
288
283
120
180 240 300 360 , 420
gelling time (minj
460
Fig. 13 The influence of LtF resins (F:U:SP =2,1:1:0,049) hardened
with oxalic acid (1) , hydrochloric acid buffered with mono-
basic ammonium phosphate (2) and ammonium chloride (3)
on gelling times .
35
-------
Results indicate that hardening of the resins by strong acids buffered with
ammonium salts of weak acids control gelling times ranging from 40 minutes
to 100 minutes at 293°K.
Resin gelling times are also temperature dependent. To enable conversion
of gelling times obtained at 293 K and 297°K into times defined by various
thermal conditions existing in soil, temperature coefficients of the resin
hardening reaction were determined . They are identical with the temperature
coefficients of the velocity of chemical reactions :
n = *g (T + 10)
where tg - gelling time evaluated at temperature T
6 JL
and t (T+IO) - at temp. T + 10
o
The sample volume of 30 ml of resins in a water temperature bath were tested
in temperatures ranging from 283 to 301 K. The hardener and the resin
were controlled at a constant temperature for 20 minutes under the measu-
rement conditions before they were mixed together . The resins investigated
were those listed in Table 10. U was dissolved in the resins immediately be-
fore they were mixed with the hardener . The resin with the ratio F:U : SP =
2.1:1:0.003 was hardened by 10 ml of 10 percent solution oxalic acid in 20
ml resin. 10 ml of 15 percent ammonium chloride in 20 ml of resin: and 0.4
ml of 36 percent HC1 and 2 g NH^i'PO. in 10 ml of solution in 20 ml of
resin. The resin with molar ratio F:U:SP = 2.1:1:0.049 was hardened by
10 ml of 10 percent oxalic acid solution in 20 ml of resin : 10 ml of 15 percent
ammonium chloride solution in 20 ml of resin : and 1 ml of 36 percent hydro-
chloric acid and 2 g of ammonium dihydrogen phospate in 10 ml of solution.
in 20 ml of resin.
The gelling times obtained at different temperatures are given in Figures 12
and 13 . Calculations of temperature coefficients of the hardening reaction
of UF resins modified by SP was n - 2 .3:2 .6 for acids and oci/la hnffprpd
with monobasic ammonium phosphate but for ammoni nn • ; •'••
Test results , however, showed the SP modifications 1o have no mHuence
on the estimated n values . Exceptionally high temperature coefficients,
estimated for the velocity of hardening of resins with ammonium salts, re-
sult from the variable catalyst density (hydronium ions) and depend on the
velocity of F reaction with ammonium ions .
Resin gelling time was found to be related to an increase of solution visco-
sity which begins occuring the very moment the resin is mixed with the har-
36
-------
120
PH
O
o
o
100 J
90
80
70
60
50
40
30
10
293°K
8 10 12
14 16 16 20
time (min)
Fig . 14 Changes of viscosity during gelling time
of30%resin solution (F:U:SP = 2, 1:1:0, 049)
hardened with oxalic acid.
37
-------
60
360 4ZQ 480
time \mir\]
Fig. 15 Changes of viscosity of 30 °/o UF resin solution
(F:U:SP= 2 .1:1:0.049) during hardening with
ammonium chloride (l) and ammonium chloride
buffered with hexamethylenetetramine in quantities
0,50g (2) , 2.0g(3) , and 4.0g (4) .
38
-------
5,
W
ex
100
90
80.
70
60.
en
o
30
20
10
fcl
296° K
^
N
120 240 360 480 600 720 640 960 10GO tfOO 1320
time (minj
Fig. 16 Changes of viscosity (l) and pH (2) of 30% UF
resin solution (F:U:SP = 2, 1:1:0 .049) during
hardening with ammonium chloride buffered
with thriethylenetetramine.
39
-------
dener. To characterize changes of viscosity during gelling process, visco-
meter investigations were carried out on the chosen resin of the following
ratio F:U:SP= 2 .1:1:0.049 . Resin with properties given in Table 8 was
hardened by the following, after U was dissolved in it.
1 50 ml of 10 percent oxalic acid in 100 ml of resin ;
2 50 ml of 15 percent ammonium chloride solution with 100 ml of resin ;
3 50 ml of 15 percent ammonium chloride, with addition of 0.5, 2 and 4g
of urotropin to 100 ml of resin ;
4 50 ml of 15 percent ammonium chloride solution and 2.5 ml of triethyle-
netetramine to 100 ml of resin.
Measurements were carried out at temp. 293 - 0.2 K, 295 - 0.2 K, 296 -
0.2 K. Changes of solution viscosity were registered in time intervals of
approximately 15 minutes. Figures 14,, 15, and 16 illustrate the course of
the changes .
Results obtained with the resin solution hardened by the acid gradually chan-
ges its viscosity. Viscosity changes are comparatively small for 1/2 to 2/3
of the gelling time . In the last period viscosity increases markedly .
On the other hand resin solution hardened by ammonium chloride (Figure 14)
or ammonium chloride with amines added to it (Figures 14, 15 and 16J are
characterized by the rapid transition of low-viscosity solution into gel. with
a gradual increase of the concentration of hydronium ions .
STABILIZATION OF SOIL WITH UF RESINS MODIFIED BY SP
UF resins introduced to the soil stabilized it after hardening. Investigations
of the properties of soil strengthened and sealed by UF resins SP modified
were carried out for the resins of following molar ratio F:U:SP =2.1:1:0;
2.1:1:0.003; 2.1:1:0.0097; 2.1:1:0.049; and 2.1:1:0.097. Table 12 illustra-
tes properties of the resins used in these experiments .
Resin solutions of the concentration 15,20,25,30 and 40 percent were harde
ned with oxalic acid at a pH 2. The samples of stabilized soils were stored
underwater during 7 clays. After this period they were tested for uniaxial
compressive strength and their coefficients of-permeability. The obtained
results are given in Figures 17 and 18.
40
-------
IZ-IO
30 AQ
resin concentration (%)
Fig , 17 Compressive strength of soil samples stabilized
by UF re'sin modified by SP hardened with oxalic
acid
1
2
3
4
5
F:U:SP =
F:U:SP -
F:U:SP =
F:U:SP =
F:U:SP =
2 1:1:0
2,1:1:0,003
2,1:1:0,0097
2,1:1:0,03
2 1:1:0,049
41
-------
20
30 40
resin concentration (%)
Fig.18 Coefficients of permeability k of soil samples
scaled with UF resin modified by PS hardened
by oxalic acid
1 F:U:SP = 2,1:1:0
2 F:U:SP = 2,1 :1:0,003
3 F:U:SP = 2,1:1:0,0097
4 F:U:SP = 2,1:1:0,03
5 F:U:SP = 2,1:1:0,049
42
-------
TABLE 12. PROPERITIES OF UF RESINS MODIFIED BY ADDITION
OF DIFFERENT QUANTITIES OF SP
Reagents
molar ratio
F:U:SP
2.1:1:0
2.1:1:0,003
2.1:1:0,0097
2.1:1:0,030
2.1:1:0,049
2.1:1:0,097
Viscosity
at 293°K
(cP)
20 - 1
22 - 1
24 - 1
22 - 1
22 - 1
23 * 1
i_ , ,_-__
Density
at 293°K
(g/cm )
1
1 .170
1 .170
1 .173
1 .178
1 .179
1 .189
i
Dry
residue
(•/•)
44
44
44
45
46
48
i
L
pH
7.0 +- 0.2
7.0^ 0.2
7.0^ 0.2
7.0* 0.2
7.0* 0.2
7.0- 0.2
In the case of resins of the molar ratio F:U:SP= 2.1:1:0.097, the stabilized
soil samples swelled and cracked when placed in water . For this reason
they were not tested. Results of soil samples given in Figure 18 with resins
of 40 percent concentration and molar ratio F:U:SP = 2.1:1:0.003 have the
maximum uniaxial compressive strength 1.15'10 N -m . The increase
of resin concentration and quantity of SP used for modification are follo-
wed by a decrease of coefficients of permeability of the soil samples sealed
with resins hardened by oxalic acid . The influence of modification in highly
noticeable especially with small resin concentration of 15 percent and 20
percent. For those concentrations the decrease of sand coefficient of per-
meability from 6 • 10"2 m • s to 2 . 3 • 10" 7m -s 1 and 2 .3 • 10" 8m • s" 1 was
obtained at the reagents molar ratio F:U:SP = 2 .1:1:0, 049 (Figure 18) .Two
kinds of resins were chosen for the further investigations of the problem
of sealing of the soils having comparatively high water permeability. The
resins were F:U:SP with a molar ratio of 2 .1:1:0.049 and F:U:SP with a
molar ratio of 2.1:1:0.003.
For the investigations of the chosen resins ammonium chloride was used to
measure effects of soil strengthening and sealing. The samples were made
from sand, stabilized with resin solutions of concentrations 15, 20, 25, 30,
35 and 40 percent. They were further hardened by ammonium chloride to
the quantity of 6.5 percent weight in relation to 45 percent of resin solu-
tion. The tests for compressive strength were made after 7 clays of samples
43
-------
30 40
resin oonrpnlrntion 0£J
Fig. 19 Compressive strength of soil samples stabilized with 111'1
resin modified by SP hardened with ammonium chloride
1 - F:U:SP = 2.1:1:0.003
2 - F:U:SP = 2.1:1:0.049
44
-------
Fig.20 30 percent UF resin modified by SP have molar
ratio (F:U:SP = 2.1:1:0.003) filling the space
among sand grains. Enlargement 200x. Microsection
taken by differential method with use of MPI - 5
microscope.
45
-------
storage under water. The results are given in Figure 19 . They denote high
strength of the soil stabilized by resins modified with SP and hardened
with ammonium salt. For example, the soil samples strengthened with 40
percent resin solution of molar ratio F:U:SP= 2.1:1:0.003 obtained a com-
pressive strength 1.41 "10 N/m (Figure 19J .
Soil stabilization impacted by the effect of SP modification of UF resin is
probably connected with polymer formation characterized by more hydro-
philic properties. Due to this, the proper structure is created especially
in the solutions dilute with acids . Hardening with ammonium chloride pro-
vides a hydrophilic polymer due to the gradual changes of pH of the solu-
tion. In this case modification with larger SP quantities appears to be
detrimental especially when the structural properties are of concern.
Soil stabilization with UF resins results from filling of pores between the
mineral grains . Adhesion to the minerals leads to the considerable stren-
gthening and sealing .
To investigate the polymer structure between the soil grains, the micro-
scopic observation of fracture surface of water stored samples and their
/ \ 1
geologic ground joints (^dry samplesj were carried out with the use of
stereoscopic microscope (enlargement x lOOJ and interference-polarization
microscopes MPI-5 (enlargements x 180j . Soils observed were strengthe-
ned with 30 percent resin solution of the molar ratio F:U:SP = 2 .1:1:0 . 003
hardened with oxalic acid . Structures of the samples stored in water envi-
ronment revealed the spaces among soil grains to be filled completely
with polymer. At the sand grain surfaces, microfissures were not observed
to exist. Microscopic obserwations of ground joints indicate that the flow
of water through the samples stabilized by UF resins is possible due to
microfissures occuring within the gel structure (Figure 2o) .
46
-------
SECTION VII
INFLUENCE OF PLASTICIZATION OF SP -MODIFIED UF
RESINS ON PROPERTIES OF SOILS STABILIZED BY THEM
OBJECTIVE AND DIRECTIONS OF INVESTIGATION
Jn order to improve the strengt.li proper-ties and water permeability of soils
stabilized by SP-modified UF resins, tests were conducted with the Follo-
wing plasticizers oF resins : (l) ethylene glycol (EG), (2) diethylene glycol
/DEC,/, (3) Furfuryl alcohol (FA), (0 e-caprolactarn (CL) and (s) acry-
loarnide (AA). In the case of acryloamide additional polymer cross-linkage
is obtained by means of polymerization. In view of its advantageous pro-
perties, the resin selected for investigation had the molar ratio oF F:U:SP =
=2.1:1:0.003 and was hardened by muriatic acid buffered by monobasic
ammonium phoshate (2.5 ml of 36 percent HC1 and 1 Og of Nil^2^0^ per
100 g of resin) . The other resin had the molar ratio of F:U:SP= 2.1:1:0.049
and was hardened by oxalic acid (at pFI 1 .8 to 1 .7 ) . In the case of the resin
containing AA, ammonium persulphate was added to the hardener as a poly-
merization initiator (l8 ml of 10 percent solution per 100 ml of resin) .
The properties of resins under investigation are shown in Table 5 . The soils
were stabilized by resins of a uniform concentration (about 30 percent) and
were examined fo>" eompressive slrength after 7 days of storage in water
and after 14 clays of storage in the open air, and coefficients of permeability
after 7 clays of storage in wafer .
PLASTICIZATION OF RESINS BY ETHYLENE GLYCOL (EG) AND
DIETIIYLENE GLYCOL (l)EG)
UF resins plastified by glycol are used as grouts; i.e., Soviet ME-17
resin » lj. In view of a relatively high cost of glycols, they were added
in ratios of 2.5 to 15 parts of volume per 100 parts of resin.
The strength tests carried out for soil samples stabilized by these resins
shows (Tables 13 and 14J samples stored in water reach a higher strength
in the case of the DEC plasticizer (s.5'106 N/m ) at 5 parts by volume
of DEC, per 100 parts of resin and F:U:SP= 2 .1:1:0 .003 and 3 .58-10° N/m2 at
47
-------
TABLE 13. INFLUENCE OF PLASTICIZATION OF SP-MODIFIED UF
RESINS BY MEANS OF EG ON THE COMPRESSIVE
STRENGTH AND THE COEFFICIENT OF PERMEABILITY
OF SOILS STABILIZED BY THEM
Molar
ratio
F:U:SP
in resin
2.1:1:0.003
2.1:1:0.049
EG content
(EG parts of
volume per
1 00 p .0 .v .
of resinj
2.5
5
7 .5
10
15
2.5
5
7 .5
10
15
Compressive strength
(N/m2)
samples
stored
in water
C
6 .64-10
6.36:106
6.20:106
5 .62-106
5 .50-106
2.90-106
2.74'10f3
3.18-106
3 .34-106
2.98-106
samples
stored
in the
open air
7 .70: 106
3-80:l06
3.43:106
3.08-106
3.68-106
2.04-106
2 . 28 ' 1 O6
2.41 -106
2.29-106
2.26-106
Coefficient
of permeabi-
lity
(m/s)
3-1 -10"9
- 9
3-G'lO
4.5 -10" 9
8.5 -10"9
1 .7 -10"9
3 .8-10'9
9.0'10-]°
6.6-10" 9
- 9
2.7 -10
6.3-10"9
48
-------
TABLE 14. INFLUENCE OF PLASTICIZATION OF SP-MODIFIED
UF RESINS BY MEANS OF DEC ON THE COMPRESSIVE
STRENGTH OF SOILS STABILIZED BY THEM
Molar
ratio
F:U:SP
in resin
2.1:1:0.003
2.1:1:0.049
j
DEC content
(DEC parts of
volume per 100
p .0 .v .of resin)
2.5
5
7.5
10
15
2.5
5
7 .5
10
15
( 2^
Compressive strength (jNT/m )
_
samples
stored
in water
*" - 1
7 .65' 106
8.05 • 106
7.85- 10G
7 .65-106
7.10-106
i .,
3.19-106
3.14-106
3.06'106
3.38-106
3.58-106
r
samples
stored
open air
2.34-106
2.39-106
1
2.82'IQ6 '
1
2.99'IG6
I
2.94-106
1 .41 -106
1 .72-10°
1 .95 -10°
2 .00-106
2.39-10°
49
-------
15 parts by volume of DEC per 100 parts of resin and at F:U:SP=2 .1:1:0.049 .
In the case of the E G plasticizer a continuous fall of strength is recorded
for the resin of the molar ratio F:U:SP = 2.1:1:0.003. A slight maximum of
strength is recorded for the resin of the molar ratio F:U:SP= 2 . 1:1:0 . 049
at 15 parts by volume of EG per 100 parts of volume of the resin.
Similar changes occur in the compressive strength of samples stored in the
open air (Tables 13 and u) . As a result of glycol addition, a drop in the
compressive strength was obtained in the case of the resin of the molar
ratio F:U:SP=2 .1:1:0.003. On the other hand plasticization of the resin
of the molar ratio F:U:SP= 2.1:1:0.049 results in an increase of strength
to2.41-106 N/m2 (for EG) and to 2.39-106 N/m2 (for DEG) .
Water permeability through the EG plasticization stabilized soil sain pies
does not depend on the volume of the added glycol. Coefficients of permeabi-
lity range between 0.9 '10 m/s for both kinds of resins under investiga-
tion (Tables 13 and 14) .
PLASTTC1ZATION OF RESINS BY FURFURYL ALCOHOL (FA)
23
FA addition to UF resins was attempted to raise properties of resin
In the tests, FA was added 0.5 to 4 parts of volume per 100 parts of volu-
me of resin. Strength measurements carried out for soil samples stabilized
by resins prepared in this manner have shown that soil samples stabilized
by the UF resin of the molar ratio F:U:SP = 2.1:1:0.003 and stored in water
(Table 15) indicated a drop in strength along with the increasing FA con-
tent in the resin. On the other hand the compressive strength of soil sam-
ples stabilized by the UF resin of the molar ratio F'U:SP = 2 . 1: 1 : 0 . 049
increases as a result of plasticization up to4.60'10 N/m . Decrease
of the compressive strengt of soil samples stabilized by the resin (F:U:SP =
= 2.1:1:0.003) plastified by FA was also noted for Ihose stored in the open
air. The samples stabilized by the resin (F:U:SP = 2 . 1 :1 :0 . 049) plastic Lzed
by FA increase their strength up tol.32'103 N/m" along with the growing-
content of plasticizer . Water permeability of the stabilized soil samples was
not affected by the FA content which oscillate between l.l-10V^and 1.3 -10"9
for both the resins under investigation (Table is) .
PLASTICIZATION OF RESINS BY E-CAPROLACTAM
CL is a widely used plasticizer of UF resins . No mention was found in the
available literature of its application as a component of UF grouting solu-
tions . In these tests, CL was varied 0.5 to 8 parts by weight of resin.
Measurements have shown an increase of strength in the case of samples
stored in water (Table 16) due to plasticization . The maximum measured
values were obtained on the resin of the molar ratio F:U:SP = 2 . 1 :1 :0 . 003 and
-------
TABLE 15. INFLUENCE OF PLASTICIZATION OF SP-MODIFIED
UF RESINS BY MEANS OF FA ON THE COMPRESSIVE
STRENGTH AND THE COEFFICIENT OF PERMEABILITY
OF SOILS STABILIZED BY THEM
Molar
ratio
F:U:SP
in resin
p-------~-------
2.1:1:0.003
2.1:1:0.049
FA content
(FA parts by
volume per
100 p.o.v .
of resin)
__ -_..__ .. .. _ra
0.5
1 .0
2.0
4.0
0.5
1.0
2.0
4.0
L
Compressive strength
(N/m2)
samples
stored
in water
_______
7 .16- 106
6.93- 106
6.67 ' 106
6.05' 106
3.69- 106
4.13- 106
4.34- 106
4.60- 106
samples
stored
in the
open air
i
3.89- 106
/-»
4.63' 10
f>
2.00' 10
1 .23' 106
0.94- 106
0.89' 106
1 .24' 106
1 .32- 106
Coefficient
of permeabi-
lity
(m/s)
3.6- 10"9
4.4 • 10"9
- 9
4.5' 10
2.3' 10"9
1 .1 • 10~8
3.3- 10~9
1.3- 10"9
4.7 ' 10~9
51
-------
TABLE 16. INFLUENCE OF PLASTICIZATION OF SP-MODIFIED
UF RESIN BY MEANS OF CL ON THE COMPRESSIVE
STRENGTH AND THE COEFFICIENT OF PERMEABILITY
OF SOILS STABILIZED BY THEM
Molar
ratio
F:U:SP
in resin
2.1:1:0.003
2.1:1:0.049
r
CL content
(CL parts of
weight per
100 p.o.v.
of resinj
0.5
1.0
2.0
4.0
8.0
0.5
1 .0
2.0
4.0
8.0
Compressive strength
(N/m2)
samples
stored
in water
8.87 • 106
8.12- 106
9.04- 106
9.15 • 106
9.26' 106
_
4.67 -106
4.97' 106
4.40- 106
4.47" 106
3.79' 106
samples
stored
in the
open air
10.79- 10G
12 .08- 106
11 .14' 10G
10.81 ' 106
5.16' 106
0.48- 106
0.75' 10G
0.71 • 106
6.61 ' 106
4.90- 106
Coefficient
of permeabi-
lity
(m/s)
1 .9' 10~9
- 9
3.5 -10
2 .2 '10~9
1.8- 10~9
4.0' 10"9
(
2.4' 10"9
1 .4' 10~9
1.9-10-10
1 .8' 10"9
- Q
1.0-10
52
-------
TABLE 17. INFLUENCE OF AA ADDITION TO SP-MODIFIED UF RESINS
ON THE COMPRESSIVE STRENGTH AND THE COEFFICIENT
OF PERMEABILITY OF SOILS STABILIZED BY THEM
Molar ratio
F:U:SP
in resin
2. 11:1:0. 003-0. 0084
2.13:1:0.003:0.021
2.15:1:0.003-0.042
2.28:1:0.003-0 .16
2. 11:1:0. 049:0. 0084
2.13:1:0.049:0.021
2.15:1:0.049:0.042
2.20:1:0.049:0.084
2.28:1:0.049:0.16
Compressive strength
(N/m2)
samples
stored
in water
7 .14 ' 106
5 .35- 106
3.49- 106
2 .06- 106
2.06' 106
2.18' 106
2.56'IQ6
2.28* 106
samples
stored
in the
open air
7 .28- 106
4.78' 106
2.30- 10G
5.35' 106
*-i
0.29- 10
0.55- 106
£»
0.45 • 10
0.96' 106
0.96' 106
Coefficient
of permeabi-
lity (m/s)
- 9
7.3-10
5.1 • 10'9
8.6' 10"9
4.0- 10~9
2.2- 10"9
1.7- 10"9
5 .8 -10"9
- 9
1.0-10
3.9" 10"9
_ _ _ __
53
-------
8 parts by weight of CL per 100 parts of weight of the resin (9.26-10 N/m )
and in the resin of the molar ratio F:U:SP = 2.1:1:0.049 using one part by
weight of CL per 100 parts of weight of the resin (4.97 -10b N/m ) . CL also
raises the compressive strength of samples stored in the open air .^ Resig
of the molar ratio F:U:SP = 2.1:1:0.003 had strengths ofl2.08'10 N/m"
as a result of addition of 1 .0 parts of weight of CL per 100 parts of weight
of the resin. Resin of the molar ratio F:U:SP = 2 .1:1:0 .049 and 6 parts of
weight of CL per 100 parts of weight of the resin resulted in a maximum
.strength of6.61'106 N/m2; i.e., where no stresses due to humidity chan-
ges are recorded.
PLASTICIZATION OF RESINS BY ACRYLOAMIDE (AA)
*>
Publication of results on soils stabilized by UF resins containing AA indi-
cate they increase strength and water impermeability. AA is however
relatively expensive and raises the stabilization costs . For this reason
AA was added in small quantities of 0.0084 0.16 mole per 1 mole of
urea. The resins had at the same time a constant molar ratio of F:CONHr,=
= 1.05:1 .
Strength tests on the soil samples stabilized by resins prepared in this
manner (Table 11) have shown that samples stabilized by the resin of the
molar ratio F:U:SP = 2.1:1:0.003 are characterized by a strength decrea-
sing along with' the growing AA content, both in the case of storage in
water and in the open air . Only in the case of samples stabilized by the resin
of the molar ratio F:U:SP = 2 .1:1:0.049 shows a slight increase of strength
as the AA content increase. It was also found that within the range of tes-
ted AA concentrations , water permeability of the stabilized soil samples
was not significantly affected.
CONCLUSIONS
Within the limits of this investigation, the best results were obtained with
SP-morJified UF resins plasticized by e-caprolactam. The soil samples
stabilized by the plasticized resin of the molar ratio F:U:SP = 2 .1:1:0 .003
showed an increase of the compressive strength of about 50 percent if sto-
red in water and about 100 percent if stored in the open air, as compared
with the values obtained for non-plasticized resins . Similarly in the resin
of the molar ratio F:U:SP= 2.1:1:0.049 soil stabilized by plasticized resins
have shown an increase of the compressive strength of about 60 percent if
stored in water abd about 20 times if stored in the open air, as compared
with the values obtained for the nonplasticized resins .
Application of other plasticizers : EG , DEG, FA or AA has brought only a
slight increase of strength or, in some cases, even a drop of strength. PlasH-
cization of SP-modified UF resin by EG,DEG, FA and AA has na major in-
fluence on the water permeability of soils sealed by these resins either.
54
-------
SECTION VIII
AGING CHANGES IN SOILS STABILIZED BY SP-MODIFIED UF RESINS
Soils stabilized by UF resins are characterized by long-term durability. 17,
19, 24, 25 The hitherto published results indicate however certain changes of
their properties. Investigations in this respect usually concern short periods
and do not combine changes of permeability and strength. In the case of appli-
cation of SP-modified UF resins to stabilization, additional aging effects con-
nected with modification should be expected.
In order to determine the aging changes in the SP-modified UF resins the
following tests were conducted on soils stabilized by them:
a compressive strength test on samples stored in water,
a compressive strength test on samples stored in air at the relative
humidity of 45 - 60 percent
a test concerning the coefficient of filtration on samples stored in
water.
> i
Samples were stabilized by 30 percent resin solutions of the molar ratios
of F:U:SP = 2. 5:1:0. 0357 and 2. 5:1:0. 0583 in which urea was dissolved to
obtain the molar ratio of F:U = 2.1:1. Properties of the applied resins are
shown in Table 5. Resin of the molar ratio 2.1:1:0.003 was then hardened by
a solution of muriatic acid buffered by monobasic ammonium phosphate (o. 2
ml 36 HC1 and lOg NH^J-^PC^ in 100 ml of resin). The resin of the molar
ratio of F:U:SP = 2. 1:1:0.049 was hardened by a solution of oxalic acid at
pH 2. After 24 hours the samples were removed from molds an1' c ' - j
under the formerly described conditions.
Tests concerning the uniacial compressive strength and measurements of
the coefficient of filtration were carried out after 1, 2, 4, 7, 14, 30 and
90 days. Results obtained for samples stabilized by the resin of the molar
ratio F:U:SP = 2.5:1:0.003 are shown in Figure 21 and for those stabili-
zed by the resin of the molar ratio F:U:SP = 2.1:1:0.049 in Figure 22
ratio F:U:SP = 2,1:1:0.003, showed the strength of the soil samples stored
in water increases up to the seventh day reaching the value of 6.05. 106
N/m2. Afterwards it falls, quickly between the seventh and twenty first
55
-------
day after reaching the maximum value and the slowly decreases through the
ninetieth day. After 90 days, the uniaxial compressive strength reaches
4. 68-106 N/m2. Changes of strength of samples stored in the ooen air were
quite similar to those stored in water. The maximum strength (5.75- 10
N/m2) occurs a little earlier, namely after 4 days. Then a fall of the
strength to 4. 76- 106 N/m2 after 90 days of storage. This decrease is
particularly quick between the 7 th and the 30 th day of storage.
Results concerning the sample strength were closely paralleled with the chan-
ges of the coefficient of permeability. The maximum strength of samples
stored in water Corresponds with the maximum value of the coefficient of
permeability- 5. 2- lO'7 m/s. Then, between the 7th and the 30th day, a rapid
decrease of the coefficient of permeability (down to 1. 9. 10~9 m/s)oceund si-
milar to the decrease of strength. Afterwards the value of the coefficient
remains rather stable and amounts to about 1. 10"^ m/s (Figure 21 j.
Samples stabilized by the resin of the ratio F:U:SP = 2.1:1:0.049 and harde-
ned by oxalic acid indicated the maximum strength (2. 93- 10^ N/m^occured
after 14 days of storage in water (Figure 22). After reaching the maximum
value, the strength drops rather quickly to 2.61*10° N/m2. Samples stored
in the open air revealed no maximum strength, and decreased from 2. 48" 10^
N/m2 after the first day to 2. 9" 105 N/m2 after 90 days. The most rapid
dall of strength occurs between the 7th and the 14th day (from 2. 04" 10^' to
5. 6« 10 N/m2J. Coefficient of permeability results presented in Figure 22
shows the maximum value of the coefficient of permeability (2. 1" 10" ^ m/sj
for the resin of the molar ratio F:U:SP = 2.1:1:0.049 was obtained about the
same time as the maximum strength of samples stored in water. The chan-
ges of the coefficient of filtration recorded in this cas"e are, similarly to tho-
se of the compressive strength, relatively small,
The maximum strength values of samples stabilized by resins of the molar
ratios F:U:SP = 2.1:1:0.033 and 2.1:1:0.049 and the maximum values of the
coefficient of filtration correlated with them, result from changes undergoing
in the hardened resin (polymerj structure. At the maximum strength, the
polymer probably reaches the highest rate of cross- linkage or the lowest
swelling capacity. The decrease of strength of samples stored in water re-
corded afterwards in most likely due to a decrease of the polymer cross-
linkage as a result of a partial hydrolysis. A decrease of the rate of cross-
linkage raises the swelling capacity. Thus the size of microfissures in the
gel structure diminishes hindering water permeability. The fall of strength
of samples stored in the open air is caused by occurence of microcracks in
the polymer gel structure under the influence of stresses brought about by
changes of humidity. The resin of a more hydrophylic structure, i.e. of the
molar ratio F:U:SP = 2.1:1:0.049 is particularly subject to these stresses.
This was confirmed by results of the strength tests (Figure 22). Occurrence
of microcracks was observed by microscope in the fracture surfaces of test
samples.
56
-------
storage time fdaysj
Fig. 21 The compressive strength and the coefficient of permeabi-
lity of soil samples stabilized by SP-modified UF resin.
The strength values for samples stored in water (ij and
in the open air (2), the coefficients of permeability kw (¥).
57
-------
7,
6
1
bfl
0
10 20 30 40 50 60 70 60
90
storage time (days)
Fig. 22 The compressive strength and the coefficient of per-
meability of soil samples stabilized by SP-modified
UF resin of the molar ratio F:U:SP = 2.1:1:0.049.
The compressive strength of samples stored in water
(l) , and in the open air (2j , the coefficient of per-
meability of samples stored in water kw
58
-------
20 40 60 80 100 120 (40 160 180 200 220 2«50 260 280 300
storage time (days)
Fig. 23 Changes of compressive strength of soil samples sta-
bilized by UF resin hardened by various hardeners: oxa-
lic acid (ij , ammonium chloride (2) and muriatic acid
buffered by monobasic ammonium phosphate (¥) .
59
-------
The course of aging changes in soil samples stabilized by UF resins also
is influenced by the kind of applied hardener. Tests carried out on soil
samples stabilized by a 30 percent resin solution of the molar ratio F:U:SP =
2.1:1 = 0.003 (after U was solved) was hardened by one of the following:
1. Oxalic acid solution (pH 2J ;
2. Ammonium chloride (50ml of 15 percent solution per 100 ml of re sin) and
3. Muriatic acid and monobasic ammonium phosphate (_2, 0 ml of 36 percent
HC1 and lOg NH4H2PO4 per 100 ml of resin).
After 24 hours the samples were taken out of molds and put into water. The
tests were limited to the strength measurements. Prior results have been
presented between changes of compressive strength and the coefficient per-
meability for common hardeners. The compressive strength was tested
after 1, 2, 4, 7, 14, 30, 90, and 300 days. The results are presented in Fi-
gure 23. Their analysis shows that hardeners containing ammonium salts
reaches maximum strength after 7 days of storage. Resins using ammonium
chloride reaches 8.05-10^ N/m2 and then decreases gradually to less than
7. 10" N/m . Muriatic acid buffered with monobasic ammonium phosphate
reaches a maximum strength of 6.05-10° N/m2 on the 14th day, declines
rapidly for 15 days and then continues gradually to weaken through the 300th
day to 4,10" N/m.2. The course of changes in the strength of soil samples
stabilized by resins hardened by oxalic acid is different. The strength
increases gradually up to 9.90»10 N/m2 after 300 days. The most rapid
increase was recorded op to the 14th day when the samples arrived at the
strength of 7.98-106 N/m2.
The results indicate that if certain hardeners (ammonium salts) are used
for hardening of resins, the stabilized samples will be subject to an accele-
rated aging process,
MECHANISM OF AGING CHANGES OCCURRING IN SOILS STABILIZED BY
UF RESINS
The available publications concerning ageing of stabilized soils are limited
to description of conditions of experiments and the obtained results. They do
not relate properties of the soil with changes in the polymer structure,
Rzhanitsin and Bleskina, 24 as well as Tshaykova25 have stated that soils
strengthened by UF resins are, as a rule, resistant to action of acid media
of pH>3 and neutral media or alkaline media of pH<13. With the present
state of knowledge of UF resins, the following processes may be expected to
occur in the course of aging of stabilized soils:
- hydrolysis of hardened resin catalyzed by acids and salts,
- diffusion of hydrolytic products,
- occurrence of microcracks in the polymer gel structure.
60
-------
The processes are thought to be interconnected. For instance the rate of
the polymer hydrolysis in the soil may be subject to the rate of removal
of reaction products form the medium, e.g. by means of diffusion. This
removal may be on the other hand facilitated by microcracks in the gel
structure.
Investigations concerning the mechanism of aging processes were carried
out for the SP-modified UF resin of the molar ratio F:U:SP = 2.1:1:0,003
but conclusions drawn from there may refer to all kinds of UF resins.
Hydrolysis of hardened resin catalyzed by acids
The urea-formaldehyde reaction rate and the polymer hydrolysis processes
are catalyzed by acids and by certain salts. ^o In order to determine changes
caused by acid action in the hardened resin structure elementary analyses
were carried out of the UF polymer extracted by 0. 1 HC1 (pH !_) and distilled
water (^pH 6. 5J. A through refinement ot the hardened resin providel for a
considerable limitation of diffusion impact on the results. The properties of
the resin used is shown in Table 5. Before hardening urea was solved in the
resin to obtain the molar ratio F:U:SP - 2.1:1:0.003. Ammonium chloride was
used as a hardener in ratios of 50 ml of 15 percent solution of NH4 Cl per
100 ml of resin. After 7 days the polymer was ground in a mortar and samples
of 3. 5 g each (_in relation to the dry residue mass j were taken. These sam-
ples were then extracted by distilled water (j>H 6. 5J and by 0. 1 n HC1 (^pH 1~) .
The flow rate of water and 0. 1 n HC1 through the samples amounted to about
6 ml/h. Extractions was carried out at room temperature and elementary
analyses of polymer after 1, 3, 7, 10 and 21 days for water and after 1, 3,
7 and 10 days in the case of 0. 1 n extraction by the acid. The hardend resin
underwent an entire hydrolysis and dissolved in the eluent. Based on results
characterizing the polymer structure:
% C
1. Molar ratio F:U F:U = (2)
/O \~s T _. ^» S
where: % C = % N - 0.428 and % C = % C - % C
u 1* U
2. Coefficient K^ characterizing the polymer cross-linkage rate
„ . % cu
CH
-CH -
where:
% Hn = % N. 0. 143
% H = % C • 0.167
r r
61
-------
3. Coefficient K characterizing the number of methylol groups
% C-CH2OH (4)
where: % C „, p
-CH2OH - CF - lo ^
Quantities characterizing changes in the polymer structure are shown in
Figure 24 and 25 and in Table 18. Results of water extraction of the har-
dened UF resin (Figure 24)indicate the molar ratio F:U falls down from
1.61 after the first day to 1.50 after 21 days. This is exclusively at the
expense of hydrolysis of methylol groups, as the K2 coefficient increases
form 1.85 after the first and 1.67 after 3 days to 2.37 after 21 days. The
KI coefficient does not change in the course of extraction, oscillating
around 0.95. This proves that methylene linkage which determines the poly-
mer crosslinkage rate does not undergo hydrolysis under the conditions of
this investigation.
Different changes are noted when extracting the resin with a 0. 1 n solution
of HC1 ^Figure 25j . In this case after 24 hours the molar ratio F:U dimi-
nishes to 1.46 and after 7 days to 1.29. After 10 days of extraction this
value does not change. Therefore it is considered the molar ratio F:U =
1. 29 is the limiting value for the UF hardend resin, below which the
cross-linked, insoluble structure disappears. Destruction of the polymer
results under these conditions from the hydrolysis of both the methylol
and methylene linkage. After 24 hours, the K9 coefficient characterizing
t-i
the number of methylol groups in the resin amounts to 2. 47 proving a
considerable fall of this number. After 3 days however the number of methy-
lol groups rises most probably due to an increase of concentration of amide
and amine groups resulting from hydrolysis of methylene linkage (_K = 1.92J.
Methylol groups are in balance with the amide and amine groups. Between
the 3rd and the 10th day the number of methylol groups drops slightly as
a result of a fall of the total amount of formaldehyde in the polymer. The
K2 coefficient simultaneously grows from 1.92 after 3 days to 2.06 after
10 days. During the time, the number of methylene bonds continuously
drops. After the first day of extraction, the KI coefficient amounts to 0.99
and after 3 days it reaches a relatively high value of 1.20. Between the
7th and the 10th day the number of methylene bonds in the polymer is
already practically constant (the KI coefficients oscillate around 1. 24 ) .
This value of the KI coefficient is most probably the limiting value for the
polymer. At K^ - 1,24 the hardened resin loses its cross-linked structure.
The corresponding molar ratio is F:U = 1.29. This investigation adds to
information presented earlier that shows the elementary analysis of UF
polymer stabilizing soils may be used to evaluate the ageing characteristics
connected with hydrolysis.
62
-------
2,5
2.4.
2.3.
2.2.
2.1.
2.0.
1.9.
IB.
1.7.
1.5 , 1.66 n
U.
1.3.
1.2.
1.1.
1.0 .
0.9.
0.8.
0.7.
1.64
1.62
1.60.
1.58
1.56
I.5Z
-x-
2 < 6 8 10 12 14 16 18 ZO 22
extraction time (days)
Fig. 24. Changes in the structure of the UF hardened resin
extracted by water.
1. molar ratio U:F
2. KI coefficient characterizing the cross-linkage
rate of the polymer
3. K2 coefficient characterizing the number of methy-
lol groups in the polymer.
63
-------
2.5
Z4.
2.3.
2.2.
2.1
2.0.
1.9.
1,8.
1.7
1.6 J
CM
1.5.
W.
1.3.
1.2.
1.1 .
1.0.
0.9.
0.8.
0.7.
Fig. 25.
12345. 6789 10
extraction time (days)
Changes in the structure of the hardened UF resin
extracted by 0. 1 n solution of HC1
1. molar ration U:F
2. KI coefficient characterizing the cross-linkage
rate of the polymer
3. K2 coefficient characterizing the number of me-
thylol groups in the polymer.
64
-------
TABLE 18. MEAN RESULTS OF ELEMENTARY ANALYSIS OF UF RESIN
EXTRACTED BY DISTILLED WATER AND 0, 1 N HC1
Eluent
Distilled
H2°
0.1 n
HC1
Extrac-
tion
time
1
3
7
10
21
1'
3
7
10
%N
20.78
29. 06
30.13
30.13
31.24
31.85
31.77
32.45
32.52
%C
33. 33
32. 29
32.89
33. 26
33.50
32.92
32.03
31.79
31.85
T~
1
%H : %s
i
i
5.39! 0.80
5.39! 0.64
5.42! 0.76
5.31J 0.79
5. 40 ! 0.43
1
5.47J 0.74
5.72« 0.76
5.77; 0. 60
5.77! 0.59
i.
F/U
1.61
1.59
1.56
1.58
1.50
1.42
1.35
1.29
1.29
Ki
0.93
1.00
0,97
0,89
0,91
0,99
1.20
1.25
1.23
K2
1.85
1.67
1.90
2.13
2,37
2.47
1.92
2.02
2.06
Investigation has shown that results of an elementary analysis of UF polymer
stabilizing soils may be treated as comparable criterion of aging advance
connected with hydrolysis. It should be thought that channels in the polymer
structure precede the differences in the mechanical properties and perme-
ability of sealed soils. The results indicate that hydrolysis of the hardened
UF resin in acid medium proceeds simultaneously at a high rate. To deter-
mine changes of strength of stabilized soil samples stored in a water solu-
tion. Samples were stabilized by a 30 percent solution of resin (^properties
are shown in Table 5j . Before hardening urea was added to this solution
to obtain the molar ratio 2.1:1:0.003. The resin was hardened by oxalic
acid at pH - 2;1.7;1,4;1 and ammonium chloride in 50 mln of 15 percent
solution per 100 ml of resin (_use of ammonium chloride drops pH in the
resin to 0.05J. After removal from the molds, the samples were stored in
water solutions.
Changes of pH values of the hardened resin caused by the difference in con-
centration of hydronim ions in the sample changes the properties of the
product. Compressive strength tests were carried out after 1, 2, 4_, 7,
14, 30 and 90 days of storage in acid solutions. The obtained results are
shown in Table 19. These results indicate in the aging period under inves-
tigation, two maximum strength values were recorded for samples stored
in the medium of pH 2;1.7,1.4, 1. The first one occurs between the 1st
and the 7th day and is probably connected with channels in the gel structure
caused among others by syne re sis . The other occurs between the 7th and
the 90th day was also covered by other aging tests. The computed values
of relative changes of the Compressive strength are presented in Table 19
and in Figure 26 They prove that in the time interval under investigation,
destruction of the polymer causing a decrease of the Compressive strength
65
-------
TABLE 19. MEAN UNIAXIAL COMPRESSIVE STRENGTH OF SAND SAMPLES STABILIZED BY UF RESINS
STORED IN SOLUTIONS OF pH 2.8 -:- 0.05
r
L.
Hardener
Oxalic acid
Oxalic acid
Oxalic acid
Oxalic acid
Ammonium
chloride
4
pH
L
2.0
1.7
1.4
1.9
0.05
_
1
r
n
3.90.10
r*
7.46. 10
/?
6. 55. 10
8. 25. 10
6. 37. 106
J
Uniaxial
2
"
5.97.106
6. 49. 106
5.90. 106
6
8. 20. 10
s*
6.80. 10
.
compressive
Storage tii
4
r
6. 20. 106
7.11.106
g
6.88.10
/?
7.98. 10
6.93. 106
.
stren_gth V.N
Tie in days
7
/?
6.06. 10
g
6.85.10
7.02.106
7.75.106
7.36.106
/m J
14
.
r
7.94.106
6. 79. 106
5. 71. 106
8.05. 106
£»
6. 30.10
30
L J
8.30.106
7.09. 106
6. 20. 106
7.53.106
6. 26. 106
U
90
8.95. 106
5.91. 106
5.56.106
6
6.14.10°
5. 16. 106
L
Relative
change of
strength
r
1. 00
0. 83
0.79
0.77
0, 73
CT3
-------
xi
to
d
CO 0]
(1)
tut) 0
a >
x!
o
a)
fc>
CO
CO
(U
(H
a
6
o
o
0)
x!
«H
O
1.0
0.9.
0.8
0.7
0.6
\
2.2 1.6 1.6 1.4 1.2 0.6 0.6 Q4 0.2
pH of medium
Fig. 26. Relative changes of the compressive strength
of soil samples stabilized by SP-modified UF resin
stored in water solutions of muriatic acid of
various pH.
67
-------
of stabilized soils begins at pH 2. Within the interval 0. 05 pH 2 a con-
tinuous decrease of relative strength changes are recorded which prove
advancing destruction, diminishing along with the decreasing pH values.
Hydrolysis of hardened resin catalyzed by salts and undissociated acids
The rate of the UF reaction is, apart from hydronium ions, catalyzed by
certain salts phosphates and acetates and undissociated acids. ^
Salts and acids selected for testing were: chlorides, nitrates, phosphates,
sulphates and oxalic acid, since they are frequent components of grouting
solutions as hardeners.
Samples were prepared of sand stabilized by resins at pH 2 in the amount of
1 m solution of acids or their sodium salts. Due to oxalic acid limited solu-
bility, a 0. 33 percent solution was used. Stabilization was carried out by
about 30 percent solutions of resin of the molar ratio F:U:SP = 2.5:1:0.00358
(Table 5J in which urea was afterwards dissolved to obtain the molar ratio
F:U=2. 1:1. The composition of solutions is given in Table 20. After the sam-
ples were taken out of molds they were stored in a 1 molar water solution of
the acid in question or its sodium salt. The solutions were acidified by HC1
to pH2 except for the oxalic sample. The compressive strength tests were
carried out after 14, 30, 90 and 230 days. Results are presented in Table 20
showing concentrated solutions of salts and the tested acids bring about only
slught drops of the compressive strength of the stabilized soil. The compu-
ted coefficients of relative changs of strength occurring during the 230 day
aging time are small and amount to 1-0.9. A continuous increase of strength
is recorded only in the case of hardening by diluted oxalic acid. Strength
changes were due to hydrolysis of the polymer and the catalytic action of
phosphate and acetic acid. Drops of strength of the tested sanlples are
caused by changes of the gel structure due to high concentrations of electo-
lytes. On the othe hand samples stabilized by resins containing NaHSO
NaIi2PO4 and CHsCOOH are characterized by lower strengths as compared
with those containing NaCl,NaNO3, HCOOH and (COOH)2. This is probably
due to the lower solubility of resin in these electrolytes. Based upon these
test results, introducion of physphates, solphates and acetates to the UF resin
solutions stabilizing soils is not desireable.
Diffusion of hydrolytic products
Removal of products of the UF hardened resin hydrolysis may check changes
in stabilized soils. The products consist of formaldehyde, urea and lowmole-
cukar-weighe products of the UF reaction soluble on water. Their removal
from the medium takes place as a result of diffusion described by the Fick
aquation:
dc
dn = - DF — dt (5)
dx v '
where: n = number of moles transferred by diffusion in the time dt in the
68
-------
TABLE 20. MEAN UNIAXIAL COMPRESSIVE STRENGTH OF SAND SAMPLES STABILIZED BY UF RESIN
STORED IN SOLUTIONS OF ACIDS AND THIER SODIUM SALTS
Composition of stabilizing
solztlon
.
Resin - 100 p. o. v. NaCl - 50 p. o. v.
HC1 cone, to pH 2
Resin - 100 p. o. v. , 3m NaNOg - 50 p. o. v.
HC1 cone, to pH 2
r~ i
Resin - 100 p. o. v. , 3m NaH PO - 50 p. o. v. ,
HC1 cone, to pH 2
-- - -
Resin - 100 p. o. v. , 3 m HCOOH - 50 p. o. v. ,
50% NaOH to pH2
.
Resin - 100 p. o. v. , 3m CH COOH - 50 p. o. v. ,
HC1 cone, to pH 2
r i
Resin « 100 p. o. v. , water - 50 p. o. v. ,
(COOHJ2 - 0.33% pH 2
i
r
Resin - 100 p. o. v. , 3m NaHSO - 50 p. o. v. ,
30% NaOH to pH 2
L_
Compressive strength (N/m j _j Relative !
14 days
6.99.106
7. 66. 106
r ~i
s*
5. 46.10
••
7.75.106
J
£»
5. 35. 10
1
7.70.106
_j
2.08. 106
.
Storge t
30 days
-\
6
6. 63.10
7.36. 106
1
4. 60. 206
6
7.37.10
J
£?
4.76.10
1
£?
8.55.10
2.20.106
.
ime
90 days 230 days
, 4.
r ^
fi fj
6.21.10 6.70.10
L _
T
8.30.106 7.81.106
!
+
c c
5.51.10 5.50.10
_1_
"
7.27.106
.
5.71. 106
r ^
8. 65. 106
2.03.106
L
/?
7.08.10
.
6
5.11.10
h
9.92. 1-.
.
change of
strength
i
0.95
0.94
.' 1.00
0.92
0.90
r
1.00
1
t - - . - . -
£?
2.01.10 0.92
-------
10
20 30 ^0 50 60 70 80 90
strage time (_daysj
Fig. 27. The compressive strength of soil sample" • '< >i'ili-
zed by UF resin stored in water (ij and in water
solutions of formaldehyde of pH 1. 7 and concentra-
tion 2% (2) , 4% (3) , and 6% (¥) .
70
-------
dc
direction x through the section F;D = coefficient of diffusion; — = gradient
of the molar concentration.
To find the degree to which diffusion of formaldehyde influences the rate of
the aging changes caused by hydrolysis, the strength changes were tested in
soil samples stabilized by UF resin stored in formaldehyde solutions at p'H
1.7 and concentration of 2, 4 and 6 percent and in water of pH 1.7. The
free formaldehyde concentration in samples was estimated at 1*7 percent to
2.3 percent. Diffusion of this compound from the sample to the surrounding
medium disappears in the case of samples stored in a 2 percent solution of
formaldehyde due to the lack of concentration gradient.
Samples were prepared of sand stabilized by a 30 percent resin solution of
the molar ratio F:U:SP = 2.1:1:0.003. The resin was hardened by oxalic acid
at pH 1.7, The compressive strengt of samples stored under these conditions
was tested after 7,14,30 and 90 days. The results are shown in Figure 27.
Relative strength changes computed on these amount to:
Formaldehyde concentration
in the medium (%_)
0
2
4
6
Relative change of strength
0.72
0.97
0. 63
0.72
i __„ „ „_ -
As only slight changes of strength were noted on samples stored in the 2
percent solution of formaldehyde, it is concluded removal of free formaldehy-
de by means of diffusion accelerates the aging processes in soils stabilized
by UF resins.
Occurence of microcracks in the polymer gel structure
In the course of hardening of the UF resin water solution there occurs
syneresis which results in a decrease of the polymer gel cubic capacity.
Chuvelev3° has found that the syneresis effect in capillaries is limited and
diminishes along with a decrease of the capillary diameter.
Along with the decrease of the soil grain size and corresponding capillaries
smong the soil grains, the number of miccracks in the gel structure due to
stresses caused by synersis will diminish as well. Thus diffusion of forma-
ledhyde will be hindered and the compressive strength changes in the stabi-
lized soil will slow down.
To confirm this hypothesis a number of samples were prepared of three
kinds of sans of various size grain: I - 0.12 to 0.3 mm; II - 0.3 to 0.43
mm; III - 0,43 to 0.6 mm. Sand samples were stabilized by a 30 percent
71
-------
6.4-10'
1 -- J
A
ft
fl
0)
k
•H
tn
CQ
ra
0)
f-i
DH
§
o
60 70 80 90
storage time ( days)
Fig. 28. Changes of the compressive strength of soil samples
of various size grain stabilized by UF resin in the
course of storage in water of the pH 1. 7 (l-fraction
0. 12 - 0. 30 mm, 2 - fraction 0. 30 - 0. 43 mm,
3-fraction 0. 43 - 0. 60 mm).
72
-------
resin solution of the molar ratio F:U:SP = 2.1:1:0.003 (after dissolution of
additional urea) hardened by oxalic acid at pH 1.7. Samples were stored in
water at pH 1.7 for 1, 14, 30 and 90 days. The results are shown in Figu-
re 28. Relative strength changes computed on these grounds aomunt to:
Kind of sand
Coefficient of relative
strength changes
0. 12 - 0. 3 mm
0.3 -0. 43 mm
0. 43 - 0. 6 mm
0, 96
0.92
0. 8?
Results indicate that the aging processes slow down along with the increase
of small-grained fraction in the stabilized soil. Thus the hypothesis of the
soil size grain on the course of the stabilizing UF resin destruction seems
confirmed.
AGING PROCESSES IN SOILS STABILIZED BY UF RESINS UNDER FIELD
CONDITIONS
Soils stabilized by grouting under field conditions have no homogeneous pro-
perties. The soil strength changes along with the distance from the axis of
the "rock-like" block. ' However, there have been no comprehensive
investigations in this respect, aimed at determination of the resin structure.
The aging processes under these conditions are not well known either. The
following tests were carried out for samples stabilized under field conditions
after a year' s ageing:
Uniaxial compressive strength test.
Determination of the coefficient of permeability.
Estimation of proportion of organic matter.
Chemical analysis of the polymer.
Estimation of the free formaldehyde concentration.
Estimation of the hydronium ion concentration.
The soil stabilization tests were carriedx out on the field of IMGW in Rynia
of Zalew Zegrzyhski. The treated area was situated below the underground
water surface within the range of influence of the reservoir. This provided
for a continuous contact of stabilized blocks with underground waters. The
treated soil consisted of close-grained sand with predominance of quartz of
the following size grain composition:
1------ — ______
iSize of fraction
i
" in mm
i Share of fraction
"in sample in %
up to
0.6
1
0.
0.
4
6-
43
0.
0.
5
43-
3
0, 3-
0. 25
12
0. 25
-0.2
50
0. 2-
0. 12
23
0.
0.
3,
12-
06
5
i
0.06
1.5
i
73
-------
Grouting was carried out with a resin of the molar ratio of F:U:SP -
2.5:0:0.00358 obtained on the technical scale second batch . Properties of
this resin are shown in Table 6. It was hardened by a 15 percent solution
of ammonium chloride with additional urea added in the amount of 10. 2 kg
per 100 1 of the ammonium chloride solution. The grout was prepared by
mixing 100 liters of resin with 50 liters of hardener. The scheme of the block
distribition created as a result of grouting is presented in Figure 102. After
a year' s aging, samples were taken form the block marked T-18 at various
distances from its axis. Samples had the diameter of 4.9 cm and hieght of
15 to 30 cm Figure 29 Directly after taking, the samples were put into her-
metic boxes having 100 percent humidity.
The uniaxial compressive strength tests were carried ouf on samples of the
diameter of 4.9 cm and height of 4.9 cm. These tests revealed the strength
of the stabilized soil slightly diminishes from 4. 25-106 N/m2 .to 60'106
N/m2 with the increasing distance from the axis of the stock (^Figure 30J, The
strength changes corresponds with results obtained by other scientists. Com-
paring the obtained results with estimation of the proportion of organic mat-
ter in samples, indicates the particularly low value for the outer sample
3,60»10 N/m2 is probably due to a lower polymer content.
Measurements of the coefficient of permeability were carried out on samples
drawing, a diameter of 4.9 cm and height of 4.9 cm. The obtained result (Fi-
gure 30J shows the coefficients of permeability have a constant value which
oscillates around 4. lO~6m/s. The coefficients of permeability in the stabi-
lized soil block do not depend on the place from which the sample was taken.
Concentration of resin in the grout has a decisive impact on the strength
properties and the coefficient of filtration of the soil samples stabilized by
UF resins. In order to determine the grout dilution effect, the proportion of
organic matter in the stabilized soil samples was estimated. This estima-
tion was based on an analysis of ash remaining after combustion of samples.
The samples were dried and ground to obtain a uniform powder of the grain
size 0.06 mm.
Results are shown in Figure 30 . Concentration of resin in the grout is
practically constant from the center to a distance outwardly of approximate
2/3 of the radius of the block. A serious decrease of proportion of resin
content due to dilution of the grout occurs in the sample taken 4 cm from
the edge of the block. This effect probably has a certain impact on the re-
sults of the strength teste. The marked organic matter originate from the
hardened resin filling the soil fissure. However as the tested samples were
taken in the course of field investigation, contamination with other organic
compounds, cannot be excluded. Overestimation of individual results was
probably due to such inclusions.
74
-------
9 cm
14 cm
19 cm
21 cm
26 cm
Fig. 29. Diagram showing sites from which samples were taken
out of the soil block stabilized by means of grouting
under field conditions.
75
-------
18
16
cu
+->
•fj
rt
a
o
10
2
n
CO
JN.
tn
So-
2
•
N* m
*»
strength
03
"01
compressive
Co
o
10 15 20 25 30
distance from the block axis (_cm)
Fig. 30. Changes of the compressive strength (l) and the
coefficient of permeability kw (3) and the organic
matter' content (2) as a function of the distance
from the axis of the stabilized soil block.
76
-------
Examination of UF resins based on the elementary analysis of the sepa-
rated polymer should provide for determination of ageing changes before
the influence the strength properties and permeability of the soil stabili-
zed by them. No investigations have been reported on this aspect.
Studies of the hardened UF resin stabilizing the soil samples was carried
out after separation of the polymer. Results of the elementary analysis are
shown in Table 21. The quantities characterizing the polymer were the molar
ratio F:U and the coefficients KI and K2 (Figure 3l). The results shown in
Figure 31 indicate that the polymer structure changes along with the gro-
wing distance from the block axis. This is probably due to diffusion of for-
maldehyde by underground waters which seems confirmed by a decrease of
the molar ratio F:U from 1.61 to 1.48. Along with the decrease of the
molar ratio F:U, the number of methylol groups drops and results in an
increase of the K2 coefficient from 1.38 to 2.17. Despite the acid medium,
no substantial changes of the number of methylene groups were found in
the polymer under the conditions of investigation. Dispersion of results is
higher here than in the course of laboratory tests. This is probably con-
nected with sporadic organic pollution of soil in the course of field
investigation.
Previous tests indicated that the rate of diffusion of free formaldehyde
from the soil stabilized by UF resins to underground waters frequently
determines the rate of the aging processes. To find the changes o f the for-
maldehyde concentration in the treated soil block exposed to the underground
water action under natural conditions, determination of formaldehyde was
made on solutions extracted of selected soil samples. Formaldehyde was
determined by a colorimetric method. The results of the free formaldehyde
concentration in the sample was estimated, assuming that: fa) water was
entirely separated from the polymer due to syneresis.
TABLE 21. MEAN RESULTS OF ELEMENTARY ANALYSIS OF SAMPLES
OF RESIN STABILIZING SOILS AND THE VALUES: F:U, Kx
AND K2 COMPUTED ON THESE GROUNDS
Symbol
ofsample
1
2
3
4
5
i
%N
1
26.81
28. 09
28. 23
27.93
27.15
" ~
%C
r 1
30.00
31.01
31.05
30.51
23.57
%H
5.22
4.99
5.15
5.13
3.88
F:U
1.61
1.57
1.57
1.54
1.48
Kl
r- - - - H
1.11
0,91
0.97
1. 00
0. 96
K2
1.38
2.03
1.78
1.75
2.17
This is, of course, a simplified scheme whit seems sufficient to compare
individual measuremenst. Free formaldehyde content in the sample was
estimated according to formula:
77
-------
2.6,
2.2
2.0
1.8
1.6
1.4
1.2
1.0
1.5
1.4.
13.
1.2.
1.1
'1.0.
0.9
0.8
0.7.
10 15 20 25 30
distance from the block axis (cm)
Fig. 31. Changes of the structure of the hardened UF resin
as a function of the distance from the axis of the sta-
bilized soil block
1. molar ratio U:F
2. KI coefficient characterizing the-cross-linkage
rate of the polymer
' 3. K2 coefficient characterizing the number of
methylol groups in the polymer.
78
-------
C
c.
FE'
m
W
where:
CF
C
FE
m
W
estimated free formaldehyde concentration in the sample,
determined free formaldehyde concentration in the extract,
nass of extracted sample,
per cent of water in the sample.
The free formaldehyde concentrations computed by this equation are shown
in Table 22 and Figure 32. The mean water content in the samples was
estimated as 12.1 percent. These results indicate that the free formaldehyde
concentration changes considerable with distance from the block axis, 1,54
percent to 0. 13 percent/.
Data showed a relatively rapid diffusion of formaldehyde to underground
waters. Despite a decrease of formaldehyde concentration in the block and
the changes in the polymer structure involved, no influence of hydrolysis
on the soil strength and water permeability has been recorded.
TABLE 22. ESTIMATED CONCENTRATION OF FREE FORMALDEHYDE
AND pH IN SOIL SAMPLES STABILIZED UNDER FIELD
CONDITIONS
Symbol
of sample
(Fig. 29)
1
2
3
4
5
I
Sample
weight
g
153
187
158
140
101
F concen-
tration in
the extract
%
__ -_. _
0.143
0. 123
1.230
0.098
0.0081
Estimated
F concen-
tration in
sample %
i
1.54
1.09
1.28
1. 16
0. 13
pli of the
extract
2, 3
2,5
2.4
2.7
4. 4
Estima-
ted pH in
the sample
1, 55
1.75
1. 60
1.90
3.20
Acids catalyze hardening of UF resins. On the other hand, a high concen-
tration of hydronium ions is one of the major factors causing secondary
hydrolysis of the hardened resin. Acids in excess then become undesirable
agents. To determine changes of the hydronim ion concentration in soils
stabilized by UF resins exposed to underground water action under natural
conditions, pH measurements were carried out in solutions obtained after
extraction of the taken samples. The measurements were made by an A-7
79
-------
2.8
2.6
M.
2.2.
2.0.
(.8.
V6.
1.4.
1.2
4.0.
2.
a,
3.
10 15 20 25 , .30
distance-from the block axis vcrn)
Fig. 32. Changes in the formaldehyde concentration (l),
pH (2j and the K-2 coefficient characterizing
the number of methylol groups in the polymer (3j .
80
-------
pH-meter. Estimates of the hydronium in the samples was based on simi-
lar assumptions made for free formaldehyde. The empiric relationship
between the solution concentration and its pH was while determining the
pH of the sample. Results and pH of the tested samples are shown in
Table 22 and Figure 32. They indicate that the hydronium ion concentra-
tion diminishes along with the growing distance from the block axis. The
pH values increase from 1.55 to 3.18. The increase of pH above 3 in the
outer part of the block seems favorable, as the published long-term obser-
vations results indicate high values of pH do not cause noticeable changes
the stabilized soil strength. Therefore, it is thought that diffusion of hydro
nium ions will lead to an increase of pH in the block below the critical
minimum before the polymer hydrolysis deteriorates desirable properties
of the stabilized soil.
81
-------
SECTION IX
BASIC GROUTS
SYNTHESIS OF WATER SOLUBLE ACETONE-FORMALDEHYDE RESINS
Use of UF grouts in basic soil is difficult.. and sometimes impossible.
Experiments to find suitable substitutes have been undertaken. Acetone-
formaldehyde (AF) resins were chosen for this investigation. They are
synthesized from cheap, easily available raw materials and characterized
by good solubility in water and have the capacity for hardening in an alkaline
environment.
Results of the investigations of the grout based on AF resins were compa-
red with the data obtained from the typical low-viscosity basic grout descri-
bed by the Soviet patent No. 248549. There is nothing new about the high
molecular product resulting from the alkaline condensation between acetone
(A) and formaldehyde (_Fj. Nevertheless, individual authors obtaining AF
resins for different purposes plasticiezer, laminating resins, fabric finis-
hings often represent opposite opinions as far as the required synthesis con-
ditions are concerned. Comparatively detailed receipt for AF resin synthesis,
aimed at surface stabilization of soil, is given by A. Falkiewicz, but the
resin obtained has too large a viscosity and limited solubility in water for
satisfactory application to grouting. The initial investigations series of AF
resin synthesis was made on the basis of Falkiewicz' s receipt and different
conditions for A and F condensation were introduced (^temperature, pli, time
of duration and F/A molar ratio). Sodium hydroxide, in the form of 10 per-
cent water solution, was used as a catalyser. An optimum AF resin f from
the points view of grouting soil stabilization") was obtained when the con-
densation was carreid out for 4 hours, at a temp, of 318 +5 K, at pH ran-
ge 10 to 11, with the molar ratio F:A 3. After the condensation was neutra-
lized, post-reaction mixture was subjected to vacuum distillation in order to
remove acetone, low volatile byproducts and water which was not reacted.
Distillation was continued until the resin reached a viscosity of about 30cP
(at 293°K),
Table 23 and Figure 33 and 34 illustrate the influence of F/A molar ratio
on the gelling time of AF resins and physical and mechanical properties of
sandy soil which were stabilized by those resins.
Twenty percent sodium hydroxide solution was used as a hardener for the
samples numbered through 1-3 and thirty percent NaOH solution was utili-
82
-------
TABLE 23. THE INFLUENCE OF VARIOUS MOLAR RATIOS F/A ON THE CHANGES OF AF RESIN
GELLING TIMES
No.
'
1
i -I
2 .
i— H
3
4
«~
5
Conditions of AF resin synthesis Properties of AF resin
Molar
ratio
F/A
^1.5:1
2:1
1
3:1
4:1
'
5:1
Temp.
°K
*"~
318+5°
**
1 L „,-«„.
r
i
pH
i -
time
'
v>
H
1
1
10-i-ll
4
r~ 1
Catalyse r
'
r ^
10%
10% NaOH
Density
at 29 3 OK
_1
3
g/cm j
1. 142
1.156
1. 176
1.183
L
1. 189
„ „„ „ „-„„,„„*****, &~~~-,~m-*~~-L~~m~ „_„„_.
I
Visco-
sity
at
293°K
j
L CP
1
29,2
32,6
33,1
32,5
33, 1
Gelling
time at 30%
NaOH in
quantity
1, 5 part, of
vilume .
(293°K)
min.
9
15
r
140
does not
gell. 30% NaOH
-15 part of
volume
l_
does not
gell 30% NaOH
15 part of
volume
-------
0)
0)
•H
en
S
o
o
10
10 , 20 30
Period of the sample storage under water (_daysj
Fig. 33. Uniaxial compressive strength of the soil samples
stabilized with AF resins obtained at different F/A
molar ratio
K/m-s1/
10 20 30
Period of the sample storage under water f daysj
Fig. 34. Coefficient of permeability k for the soil samples stabilized
with AF resins obtained at different F/A molar ratio.
84
-------
35 40 45 50
Content of the dry substance (weight %j
Fig. 35. Dependence between the density and the content of dry
substance for AF-3P resin (hatched area the range of
grouting AF resins")
150
100
U)
o
0 50
CD 3U J
293'K
35 4Q 45 50 55
Content of the dry substance (weight %")
Fig. 36. Dependence between viscosity and the content of dry
substance for AF - 3P resin (hatched area - the range
of grouting AF resins).
85
-------
zed for samples 4 and 5 resins. Investigations of the properties of the
stabilized soil samples were carried out after 1, 4, 14 and 28 days stora-
ge under water, at room temperature. Characteristics of the stabilized
sandy soil were determined in a manner similar to that discussed in sec-
tion X.
Investigations on the synthesis of AF resins on a semitechnical scale (^reac-
tor 0,25 m^)was made by use of previously chosen optimum conditions.
After the condensation, the neutralized post-reaction mixture was conden-
sed to a viscosity of about 140 cP at 293 K to remove undesirable low
molecular by-products. This improved the viscosity properties of the AF
resins. The resin (jmarked by AF - 3P Symbol J can be freely diluted with
water and the chemical grout of required viscosity is achieved when the
synthesis was carried out on a large scale and with use of technical raw
materials, it had no negative influence on the course of the process. Exo-
thermic reactions can be controlled by stopping steam delivery to the
reactor when the temperature of 308 K is achieved. After an increase of
temperature to 315 K, water cooling begins with temperature kept to the
required range i.e. 318+5 K. AF-3P resin indicates considerable stability
having no essential change in its physical and chemical properties after
9 months storage in an unheated store-house.
PROPERTIES OF WATER SOLUBLE AF RESIN STABILIZED SOIL
AF-3P resin stabilized soils were investigated for compressive strenhth
and permeability. Section X includes the characteristics and the way the
samples were prepared and determinations accomplished. Figure 35 and
36 illustrate dependence of AF resin viscosity on the content of dry sub-
stance in it. The content of dry substance in AF resin also decisively
influenced the physical and mechanical properties of the soil stabilized by
this resin ^Figure . 37 J, Twenty- five percent sodium hydroxide solution
(^293 K-l. 27g/cm^ Jwas used as the hardener in the quantity of 20 part by
volume. The sample was removed after storage for 14 days under water
at room temperature and uniaxial compression of stabilized soil was
conducted.
Assuming resins used for grouting in low permeable soil should not have
a viscosity larger than 30 to 35 cP (at 293°K) and resins diluted below
35 percent provides for weak strengthening and soil sealing, the ranges
adequate for grouting AF resins, were determined in the above mentioned
figures.
The low-viscosity grouting resins, AF-3J prepared for these investiga-
tions have the following properties:
-clear, with beige tone
density at 293°K -I.l46g/cm3
86
-------
35 40 45 50
The content of dry substance (weight %J
55
Fig. 37. The influence of AF-3P resin dilution on the strength
of sandy soil stabilized with it ^hatched area - the range
of grouting AF resins) .
87
-------
CJ
(fl
o
o
en
100
1 2 3
Time (^hourj
Fig. 38, The course of viscosity changes of AF grout hardened
with different quantities of 25% NaOH solution
1-10 part of volume of the hardener
2-15 part of volume of the hardener
3-20 part of volume of the hardener
4-25 part of volume of the hardener
5-30 part of volume of the hardener
88
-------
10 12
Time (_hour)
Fig. 39. The course of viscosity changes of AF grout hardened with
25% NaOH solution (25 part of hardener volume per 100 part
of AF - 3J resin volume) at lower temperatures.
^ o
0,2 K
295,5 ±
290, 5° + 0,2°K
1 -
2 -
3 - 285, 5° + 0, 2°K
4 - 280, 5° + 0, 2°K
89
-------
30.
CO
SH
O
X!
0)
s
bfl
C
CD
O
265 295 305
Temperature (Kj
Fig. 40. Dependence of AF grout gelling time
(AF - 31 resin hardened with 25% NaOH
N
solution in quantity of 25 part of volume)
on the temperature .
90
-------
Z5-IO*,
X!
to
2.0.
(D
-------
viscosity at 293°K -11.1 cP
pH -6.3
the content of dry substance -36. 1 percent
water solubility -total
content of free CHLO -3.12 percent
Temp, of ignition according
to Marcussonx -375 K
xTemperature of ignition was marked on Marcusson apparatus, type OB-306/
5511/01, made in Hungary, in agreement with PN-65/C-04008.
Hardening is influenced by various basic substances such as sodium hydro-
xide, potassium hydroxide, sodium carbonate, twenty-five percent ammonia,
guanidine carbonate, milk of lime, and thriethanolamine. These were inves-
tigated for AF-3J. It was concluded that gelling of the grout took place only
under the influence of hydroxide of alkaling metal., and a pH of grouting
composition lower than 10. Figure 38 and 39 illustrate the course of chan-
ges of AF grout viscosity hardend with twenty-five percent NaOH solution
in the quantity from 10 to 30 part of volume. By controlling the hardened
sample at the required temperature, determinations were made on a Rheotest
2 rotative viscometer produced in Eats Germany. Gelling times of grouting
composition were also determined. The composition consisted of 20 ml of
AF-3J resins and 5 ml of 25 percent sodium-hydroxide. Solutions were
tested at the following temperatures: 280.5°+ 0. 2°K; 285.5+0.2°K; 290.5°+
0. 2°K; 295.5°+ 0, 2°K; or 300.5° + 0. 2°K (Figure 4o).
Velocity of the hardening process of AF grout depends on the hardener tem-
pera^ure and the rate of dilution of AF resin. The results (Figure 38_)
shows- the hardening process is accelerated by an increase of the quantity
of 25 percent NaOH solution from twenty (20) to twenty-five (25j parts by
volume. On the other hand, caution must be exercised because the retarda-
tive effect of resin dilution predominates at 30 part of the hardener by vo-
lume. Temperature has an important influence on the gelling time of AF
grout. The gelling time of AF-3J resin hardened with 25 percent NaOH solu-
tion using 25 part by volume required 90 minutes at temperature of 300. S0!^
and to 405 minutes at a temperature of 290 5 K. Accelerating the process of
hardening of AF grout by an addition of larger quantities of NaOH water so-
lution, effecting resin dilution and reducing mechanical strength of the stabi-
lized soil (Figure 41 _) results in no essential changes of the coefficient of
permeability, (l, 10~ m/s).
Soil stabilized by AF grout resistance to the aging processes was determined
by testing the grouts mechanical and filtration properties after 1, 7, 14, 30,
45 and 90 days storage under water, at room temperature . Twenty-five per-
cent sodium hydroxide solution in the quantity of 15 part by volume was used
as a hardener for the resin stabilized soil. Figure 42 illustrates the influ-
ence of the aging process on the uniaxial compressive strength of the sam-
92
-------
tuo
O
T
K/m.s /
10 20 30 40 50 60 70 60 90
Period of the semple storage underwater (days)
Fig. 43. The influence of egeing period on the coefficient of
permeability kw of the soil samples stabilized with AF
grout.
93
-------
pies of stabilized soil. The initial increase of the strength is caused by
the soilpolymer' s second hardening. Maximum strength occurs after 35
days of aging. Compressive strength amounts to about 2. 6. 10° N/m at that
time. After 90 days of storage in water, the Compressive strength decreases
to 2.2'10^N/m2. Figure 43 illustrates changes of coefficient of permeauili-
ty (kw) during the storage of the stabilized soil samples. Coefficient of
permeability is 1. !• 10"8in« s"1 after 7 days and decreases to a minimum
value of (kw) 7. 0- 10~9m» s"1 after 30 days of aging. In the course of furt-
her aging, permeability is 1, 4- 10~8m* s after 90 days.
PHYSICAL AND MECHANICAL PROPERTIES OF LOW-VISCOSITY
PHENOLIC-FORMALDEHYDE STABILIZED SOIL
Phenolic-formaldehyde (FF) grouts are often used in preparation for soil
stabilization. Because some of them harden in alkali environment, they
can be applied to the soils containing carbonates and clay molecules. Li-
terature does not provide us with the specific-data concerning the properties
of the soil stabilized with low viscosity basic FF grouts, and therefore,
limited investigations were included as a portion of this study. The results
enable the rough estimation of both types of basic grouts.
The grout described in the Soviet patent No. 248549 was chosen for the
investigations. Components of the grouting composition were selected to
obtain a gelling time at room temperature, without thermostating, of appro-
ximately 2 hours. (Table 24j.
TABLE 24. COMPOSITION OF FF GROUT
Compositon of FF grout
Formalin solution
"A"
30%
NaOII solution
Gelling time at
room temperature
without
thermostating
part by weight
part by volume/100
parts by volume of A
solution
phenol - 1
resorcinal - 1
37% formalin - 5
ethylene glycol-0,25
2,25
115 min
Figure 44 illustrates the changes occuring in viscosity of FF grouts.
Viscosity was determined by means of Hopler1 s rheoviscometer. The measure
ments were taken every 15 minutes, starting the moment that 20 ml of
94
-------
700
600
500
400
0,
o
5" 300
to
o
o
to
zoo
100
?2
6 8
Time (hours)
10
Fig. 44. The course of viscosity changes of FF grout at
temperature
1 - 295,5° + 0,2°K
2 - 290,5° + 0,2°K
95
-------
to
v 2
>
w
to
0)
Si
6
o
U
.X—'
10 20 30 40 50 60 70 60 90
Period of the sample storage underwater (^ 24 hoursj
Fig. 45. The influence of ageing period on the mechanical resistance
of the soil samples stabilized with FF grout.
fcuO
O
K(rn-s')
10 20 30 40 50 60 70 60 90
Period of the sample storage under water (_24 hour)
Fig. 46. The influence of ageing period on coefficient of permeabi-
lity kw of the soil samples stabilized with FF grout.
96
-------
formalin solution "A" was mixed with 0.45 ml of the hardener (30 percent
NaOH solution, having a gravity of 1.32 g per cubic centimeter at 293 K) .
The samples of the hardened grout was maintained at constant tempera-
tures of 295. 5°+ 0. 2°K and 290. 5°+ 0. 2°K.
This grouting composition has a low initial viscosity, (_6 to IcP) which
gradually increases till the moment prior to gelling. Viscosity increases
rapidly as gelling proceeds. Strong dependence of the gelling time on
temperature is observed similar to the AF grouts (about 5 hours at temp.
295.5°K and about 9.5 hr. at temperature 290, 5°K.)
The samples for the investigations of physical and mechanical properties
of the soil stabilized by FF grout were prepared in the same way as for
the AF grout. Determinations of uniaxial compressive strength and co-
efficient of permeability kw were made after 1, 4, 1, 10, 21, 45 and 90
days storage of the samples under water, at room temperature. The results
are given in Figure 45 and 46.
The soil stabilized with FF grout achieved optimum properties after 45
days storage' under water. Uniaxial compressive strength totaled 3. 64* 10"
N/m2 and coefficient of filtration kw = *• 6* lO'^m/s. After 90 days aging,
certain worsening of soilpolymer properties occurs. It especially concerns
its permeability (^kw = 2. 6- 10 m/s). The general course of changes of
physical and mechanical properties of the soil stabilized by FF and AF
grouts are similar.
97
-------
SECTION X
METHODOLOGY OF INVESTIGATION
REAGENTS AND RAW MATERIALS
Reagents used in laboratory investigation
The basic reagents used in laboratory investigation included:
- pure formalin of the concentration 37 percent F stabilized by methanol
according to the standard BN-68/6191-86,
pure urea according to the standard BN-65/6191-41,
commercial sodium pyrosulphite according to the standard
PN-67/C-84016,
- pure acetone according to the standard BN-65/6191-51,
- pure resorcin according to the standard BN-72/6193-34,
- pure phenol according to the standard BN-65/6191-33,
- pure sodium hydroxide according to the standard BN-71/6191-07,
- analytically pure muriatic acid 36 percent according to the standard
BN-70/6191-90,
- pure ammonium chloride according to the standard PN-64/C-80046,
- pure monobasic ammonium phosphate according to the standard
BN-64/6191-30,
- pure ethylene glycol according to the standard BN-72/6193-34,
- pure diethylene glycol according to the standards of Koch-Light
Laboratories Ltd.,
- pure furfuryl alcohol according to the standard ZN-67/CZSP/E-11, 226,
- commercial caprolactam according to the standard ZN-64/MPCH-Sch-
196,
- pure acryloamide according to the standards of Fluka AG, Buchs SG,
pure sodium chloride,
- pure sodium nitrate according to the standard PN-64/C-80259,
- pure monobasic sodium phosphate according to the standard
ZN-62/MPCH/N-975,
- pure acetic acid according to the standard BN-69/6193-11,
- pure formic acid according to the standard ZN-69/MPCH/N-1507,
- pure hexamethylenetetraamine according to the standard PN-55/C-80552,
- commercial triethylenetetraamine.
Apart from the specified reagents the following compounds were used in
analytical work in the analytically pure state: disodium phosphate, sodium
hydroxide, sodium sulphite, mercuric chloride, sodium chloride, sodium
98
-------
versenate, iodine, sodium thiosulphate, indicator phenolphthalein, indicator
thymolphthalein, indicator fuchsine.
Raw materials used in syntheses on a semi-technical and technical scale
- commercial formalin of the concentration 36.5 to 37.5 percent stabilized
by methanol according to the standard PN-60/C-8800,
- commercial urea according to the standard PN-62/C-88029,
- sodium pyrosulphite according to the standard PN-67/C-84016,
- commercial acetone according to the standard PN-51/C-97001.
Apart from the specified materials small quantities of the following corn-
pounds were used: pure muriatic acid and pure sodium hydroxide in water
solutions of the concentration of 3 to 10 percent.
EQUIPMENT FOR SYNTHESES
Equipment used for UF and AF resin syntheses on the laboratory, semi-
technical and technical scales
Reactions on the laboratory scale were carried out in quckfit reactors of
the capacity from 0.5 to 5.0 1 furnisched with a heating jacket, mixer,
dropping funnel, reflux condenser or distillation cooler and a thermometer.
The mixer seal and the distillation set provided, if necessary, for vacuum
reactions.
Reactions on the semi-technical scale were carried out in an enamel reactor
of the capacity of 0. 25 cu m furnished with a heating and cooling jacket
steam heating , mixer, dropping funnel, heat exchanger; thermometers and
a vacuum distillation set (Figure 47j.
Synthesis of UF resins on the technical scale was accomplished by the
Plasticicis Company using the equipment presented diagrammatically in
Figure 48. Reactions were made in the three enamel autoclaves of the
capacity of 5, 3 and 2 cu m. at the same time and the resin discharged
simultaneously, providing for a homogeneous batch of resin of about 10 tons.
ANALYSES AND MEASUREMENTS
Determination of free formaldehyde in resins
Free formaldehyde in the resins were determined by means of the
sulphiteacidimetric method. 42 As a result of reaction of sodium sulphite
and free formaldehyde there occurs the sodium salt of hydroxymethanosul-
phonic acid and the equivalent quantity of sodium hydroxide which is then
titrated by a standard acid solution.
99
-------
o
o
1. 2. Weight measuring instruments
for rad materials
3. Impeller pump for liquids
4. Pressure autoclave
5. Cooler
6. Pressure Vessel for distillate
7. Resin reservoir
Fig. 47. Diagram of the semi-technical installation for AF and UF resin production
-------
11
form alin
sodium
pyrosulphite
resin
1. Formalin reservoir
2. 3. Impeller pumps for liquids
4. Formalin volume measuring in-
strument
5. 6. Urea and sodium pyrosulphate
weight measuring instruments
7. Mixe r
8.9.10. Autoclaves
11,12,13. Coolers
Fig. 48. Diagram of the installation for UF resin production
-------
Determination of formaldehyde in the extract
Formaldehyde in the extract was determined by means of the coloimetric
method worked out in the IMGW. 43 Color reaction with formaldehyde was
due to pure fuchsine. In view of a high sensitivity of the method testing
solutions were diluted 10-100 times. The determination error was less
than 1 percent.
Determination of pH
Measurements of pH of water solutions of resins and extracts were carried
out by means of a pH-meter or colorimetrically in relation to the desired
error magnitude. Laboratory work was mainly based on the 7A pH-meter
of the three measurement ranges:
I - pli 5-9, at the accuracy of + 0.05 pH,
II - pH 0-8, at the accuracy of + 0, 1 pH,
III- pH 6-14, at the accuracy of + 0.1 pH.
Semi-technical and technical syntheses were carried out by means of Bel-
gian UCB indicator papers of the range 3.0-5.0, 4.8-6.8, 6.2-8.2, 7.5-9.5
pH, providing for the accuracy of + 0. 2 pH.
Determination of the dry residue content resin concentration
30
There is no standard method for determination of dry residue content in
UP and AF resins. The basic method consists in drying. The proportional
content of dry residue was determined on the ground of the difference bet-
ween the mass of the resin sample dried at 393 + 2 K and its normal
weight 2 hours for the UF resin and 10 hours for the AF resin .
30
Determination of water and acetate tolerance
Determination of the tolerance was based on the following method: A resin
sample of 5 ml is poured into a 50 ml beaker by means of a pipette,
cooled to 293 + 1 K and while being continuously mixed, titrated up to the
moment when black traces disappear from the white surface below the
beaker. The quantity of percipitant in ml is read from the burette. The
tolerance is expressed in ml of the used precipitant per 1 ml of resin.
The used precipitants were: water (water tolerance) and a 30 percent
solution of sodium acetate (acetate tolerance).
Elementary analysis
The hardened resin samples for the proportional carbon , nitrogen, hydro-
gen and sulphur content tests were prepared by a thorough grinding in a
mortar and sixfold washing with distilled water in order to remove all
102
-------
the components not connected with the polymer. The samples were then
dried in vacuum at 308° + 2°K for 24 hours. Before the measurements they
were stored in a decinator above calcium chloride. Elementary analyses
aimed at determination of the proportional content of nitrogen, corbon and
hydrogen and ash were by means of the PERKIN ELMER 240 apparatus at
the accuracy of i1 0. 3 percent. The sulphur content was determined on the
grounds of burning the sample in the Sh'dniger bottle.
Intra-red spectrum
The infra-red spectra were worked out for the washed resin samples which
were dried similarly to those of the elementary analysis. The testing sam-
ples were prepared by pressing of the ground resin into potassium bromide.
The spectra were obtained on the UNICAM SP-200 apparatus.
STRENGTH TESTS
Selection of methods
The uniaxial compressive strength tests are the most frequently used met-
hod of determination of mechanical properties of stabilized soils. This test
was adopted as a criterion of the strength properties of the tested semples
for this investigation. Uniaxial compressive strength measurements were
made with the ZD 10/90 tensile testing machine (Made in the GDR) having
the following characteristics: Accuracy of the load measurement - i" 1 per-
cent, Shitt rate regulated between 3, 5 and 35 mm/min, Range of measure-
ments: 2.103, 4. 103, 1.104, 2« 104, 4'104, 1.10°N. The strength tests
were carried out at the shift rate of 35 mm/min. The results were based
on the mean value of three measurements.
Preparation of samples
The samples were prepared by means of mixing sand with resin. The used
sand had well segregated and encircled grain, with some of the particles
being cracked or surrounded with envelopes of hydrated ferrum compounds.
The basic component of sand was quartz (96 percent), feldspar (2.9 per-
cent) and heavy ends minerals (l. 1 percent). The sand size grain is shown
below:
FRACTION 0.8- 0.63- 0.40- 0.25- 0.16- 0.09- 0.06- 0.06
SIZE (mm) 1.0 0.8 0.63 0.40 0.25 0.16 0.09
FRACTION CON-
TENT IN SAMPLE
0.50 0.42 15.10 55.00 23.38 3.25 0.32 0.32
103
-------
Fractions of more than 0.8 mm and less than 0.06 were removed while
preparing the samples. In the case of stabilization by UF resins the sand
prepared in this manner was washed by a 1 percent solution of HC1 and
then by water in order to remove alkalic compounds and ion exchangers.
DETERMINATION OF THE COEFFICIENT OF PERMEABILITY
The kw coefficient of permeability is calculated on the relation between the
Volume of the penetrating water V within a unit time t and the surface unit
F under the influence of the hydraulic gradients I:
v
w F. 1. t
As the soil samples stabilized by polymers have a rather low water permeabi-
lity, the basic problems consist in; a precise fixing of the sample in the
testing mechine in order to avoid edge effects and measurements of small
flows. Sealing of the sample walls was obtained by means of a rubber me-
mbrane out of which the pressure was raised. The measurement apparatus
is shown diagrammatically Figure 49.
Measurements were based on samples prepared similarly to those for the
uniaxial compressive strength or taken form soil blocks stabilized by
means of field grouting. The penetrating water volume was measured witli
the accuracy of 1" 0.01 cu cm by means of a measurement reservoir furin-
shed with a scale. Measurements presented in Chapter VI gave results
which were based on the mean values of measurements for three samples.
As the results repeated, further measurements were based on the mean
vaule of samples.
MEASUREMENTS OF THE ANGLE OF CONTRACT
Measurements of the angle of contact were carried out according to the
method described by Putilova^ on the grounds of photographs of the air
pocket below the quartz plate sunk in the tested resin. This made it possible
to avoid the hysteresis of the wetting capacity. Before the measurements
the plate was throughly cleaned and deg reased by extraction with carbon
tetrachloride. In view of a considerable dispersion of the measured values
of the angle of contact within the range of i" 0.05 radian, the presented
results are based on the mean values of 10 measurements.
MICROSCOPE TESTS,
Microscope observations of the fracture surfaces of the stabilized soil
samples were carried out by means of the MSt-131 stereoscopic microscope
using magnification of 16.5-100 times to make it possible to keep the
necessary depth of field. Test of microsections of the stabilized soil
104
-------
1. Tested sample.
2. Upper reservoir of water
which presses the membrane
down in the sample.
3. Mensuring vessel.
4. Conduit joining the upper
reservoir with the device
for fixing of samples,
5. Conduit joining the measu-
•ring vessel with the device
for fixing of samples.
6. Discharge vessel.
7. Membranne which tightens
samples.
Fig. 40. Diagram of the instrument for measuring of the
coefficient of permeability of samples.
105
-------
samples were carried out by means of the interference-polarization
MPI-5 microscope. Enlargements of 60-600 times were used. Tested
samples were impregnated in a vacuum with methyl methacrylate which
was then polymerized. This provided for clean and untouched micro-
sections.
106
-------
SECTION XI
METHODS FOR COMPUTATION OF GROUT FLOW
INTRODUCTION
Equations predicting the range and duration of the injection of grout being
introduced into the soil is presented in three sections. The injection range
and duration depend on: coefficient of permeability, coefficient of soil effec-
tive porosity, filter diameter of the well pumping the grout, liquid viscosity
and magnitude of the overpressure under whitch the liquid is being intro-
duced into the soil. Computations cover the two essential cases: (l) pum-
ping the grout only, when the stabilized soil assumes cylindrical shape;and
(2) pumping the grout with displacement by other liquid, for example, by
water thus obtaining the cylindrical shape with unstabilized soil inside.
The grout flow,,can be considered to act in one of three patterns: (Aj The
coefficient of the dynamic viscosity of the grout is constant during the
incjection ( p. = constant for 0
-------
covered by the grout is inversely proportional to the dynamical viscosity
of the grout.
where:
k (t) - coefficient of permeability for the grout changeable
in time,
kw - coefficient of permeability for water,
M (t) - coefficient of the dynamic viscosity of the grout
variable in time,
Mw - coefficient of the dynamic viscosity of water.
BASIC PATTERNS FOR INJECTION PROCESS
Pattern A. - The coefficient of the dynamic viscosity of the grout
is constant during the injection /J = constant 0< t < tg
In practice, the grout does not change its capability for penetration or
these changes are practically omitted in an interval of time (o, tg),
whereas after exceeding the gelation time tg the grout gells rapidly.
The analysis has been carried out for the injection phenomenon, according
to the Pattern A (Figure 52J. It allows computation of time of the grout
for penetration, distribution of pressure in the aquifer and the grout rate
depending upon hydrogeological parameters of the area, the grout pro-
perties and conditions of pumping.
108
-------
Fig. 50. Pattern of grouting procces.
When overpressure A H occurs in time t=0 and the grout has not yet
nan.-,+ ~.r,+_ J - - J- ••-' " ' ~ "~
~ O
penetrated into the medium, the flow rate QQ amounts to:
Q.0= 2TT kw m
(9)
Where:
m
A H
R
r
aquifer thickness
overpressure introducing the grout
external radius of the aquifer
radius of the injection well
Whereas the oiezometric pressure heads h (r) are distributed according
to equation (lo)
109
-------
h(r) =
A H
1 -t-
Ln -f
lo
In JL
(10)
Where:
r - distance from axle of feeding hole
If after time (t) the grout penetrates on a distance rB , the piezometric
preassure head h (TB) on the border line of two liquids can be determined
from the equality of the flow rates in the aquifer and in the layer being
injected:
2TTmk
2TTmkw
hence
To
In
where:
k - coefficient of permeability of the soil covered by the inje-
ction, computed according to the formula
Indirect piezometric pressure head is computed according to:
h(r)
h(rB)+- -
h(rB)
. r
1 n-f-
1 1
In-B.
r
AH-h(rB)
. p
n— •
1 I r°
In-^-
r
for r0<.r
-------
The volume of flow depending upon the grout radius can be computed
according to one of the two following formulas:
-
ra
(13)
or
Q
2TTkwmAH
JJL
I o
(14)
Flow velocity on the border line of two liquids amounts to:
V(rB>
2TT m ran
By introducing into the formula (.15) the Q computed according to the
formula (l4J reveals:
nra |n-B-+ k*Lin IB.
To K To
(16)
Having computed the flow-velovity on the border line of two liquids, depen-
ding upon the distance rB time of the inject penetration for the distance
ra can be computed as follows:
n- /4^
v v (r
»4 T \' I
[nR -
(17)
r.'
111
-------
The derived analytical formulas enable carrying out the analysis of the
injection phenomenon and the selection of the optimal conditions for intro-
ducing the grout into the soil. Having possibility of computing the time of
the grout penetration for the distance (r6) , the flow velocity on the border
line of two liquids and the injection rate, the magnitude of the pressure
pumping head (A Ii) as well as the gelation time (tg) of the grout can be
adjusted adequately for obtaining the stabilized block of the required dimen-
sions.
For the pattern A the two programs for computation on the WANG 2200 mi-
nicomputer have been constructed:
(ij Program Al is used for the computation of penetration time of the
grout for a required distance ,
\2\ Program A2 is used for the computation of the grout radius for a
given time.
Both of the programs enables computation of the injection rate. Printouts
of the programs are presented in the Appendix A. Figure 53 and 54 show
graphically the results of computations according to the programs Al and
A2 for the selected example:
AH = 10 m
R = 100 m
r0 = 0,1 m
kw = 5 x 10~4 m/s
k 5 x 10"5 m/s
n = 0. 1
PATTERN B - The coefficient of the dynamic viscosity of the grout chan-
ges in time at same rate in the whole aquifer
JLJ = ju(t) for 0
-------
o'5- Q/
m
MS] [s]
3-
-S-
10
Cm]
Fig. 51 Dependence of time and of the injection rate
on the radius range rb of the grout, according
to the pattern A f computation with the program A l)
113
-------
10'5- Q/i
[m2/s]
m
10
Q/i
m
B
10
t-1000
Cs]
Fig. 52 Dependence of the radius range ra of the grout
and of the injection rate on the injection duration,
according to the pattern A (computation with the
program A 2J.
114
-------
Knowing the grout dynamical viscosity changes in time M\i) , the value k (t)
is calculated according to formula (_8j. In each step the mean coefficient
of permeability is assumed. Thus the function k (t) is replaced by the con-
stant function in the particular intervals (Figure 53\
Fig. 53 Time discretization of the function k (t) .
The range of radius of the grout r' in an optional time step "j" can
be computed knowing the volume or the grout introduced into the soil
from the very beginning of the injection to the end of the jtn step (Fi-
gure 56) .
TV;!.- WATERED AREA
GROUTED AREA
0 r
B
Bj
Fig. 54 The axial-symmetrical sector of the filtration area with
situation in the j time step, for the pattern B.
115
-------
Assuming dependence
Vj =TTmn (r^2- r/) (is)
one can determine the range od radius of the grout in the j time step:
Vi . . (19)
TTmn °
where:
V. - volume of the grout introduced from the very beginning
of the injection to the end of the j™ time step,
r - range of radius of the grout in the soil in the j time
3 step,
m - aquifer thickness
n - effective porosity of the medium.
The magnitude of V-; is computed from dependence
V. = V. , + A V. (20)
J J-1 J V J
where:
V. - volume of the grout in j-1 time step
J
The increase of the grout volume in time A t. amounts to:
J
V. - Q . At. (2l)
J J J ^ J
where:
At. - j time step
J
Q. - mean flow rate in the j time step.
The mean flow rate in the j time step is computed as the arithmetic
mean of the final rate in the j-1 1time step and of the rate in the jtn step
computed according to the formula:
11.6
-------
_. 21T m AH
1 i IB) , l_ i _K
kj r° kyv Tgi ^ -.
J (22)
Since the formula (22) includes r'g-j, i.e. the value which is searched
for, the solution should be sought by application of the iteration process.
Values QJ are assumed in each iteration step of the iteration proces.s
according to the computation in the preceding iteration step. In the first
iteration of each time step it is assumed that:
Q3 = V
u u
whereas in the first time step it is assumed:
Q = o, 5 (Q + Q ) (23)
where:
Q - flow rate before injecting, according to
the formula
The above mentioned iteration process leads to the inequality
< & (24
where:
Q, - rate value computed in the preceding iteration step
J
& - optinally small number greater than zero.
For pracitcal computation it may be assumed as &= 0,001.
If we assume:
Qi = 2TTAH
m "i '. nTi
(25)
117
-------
and further
(26)
as well as
V.
'i = •=•
J m
y. = v + A v.
then the formula 19 will take a form:
Tin + r°
To follow the computation process more easily, flowchart is given in figu-
re 57.
The above method of the solution of the injection problems for the pat-
ter B has been presented for a case, when socalled "bulb" is to be made
as a result of the injection. Then the grout fills the aquifer limited by
the calindrical surfaces of radii TB a^d r0, A derivative problem is a
matter of computation of the injection range, injection rate etc., in con-
ditions when the inject already introduced into the soil is being displaced
by other liquid. As a result of the grout stabilization the bulb of a shape
similar to a cylindrical ring will be then created. For the pattern B,with
displacement, the solution is obtained similarly to the above, with so-
me of the given formulas subject to the modification:
118
-------
C STOP
Fig. 55 Flowchart of the program .Bl
119
-------
2TIAH
r.
1 . R
:— In -r-
kw rB;
for j<
for j > N<,
rBj
(28)
where:
N.
r . -
wj
k, -
number of the step by which displacement of the grout
introduced previously is being started,
range of the radius of the displaceing liquid,
coefficient of permeability for the displaceing liquid.
The range radii of the inject and of the displaceing liquid are computed
according to the following formulas:
Bj
LL
'Tin
+
(29)
wj
W]
Tin
+ r.
(30)
where: v
J
sum of volumes of the grout and of the displaceing
liquid in the soil, in the jtn time step divided by m
volume of the displaceing liquid in the soil., in the j^
time step divided by m
with
v + v
j
(31)
120
-------
For the pattern B the two programs for computation on the WANG 2200
minicomputer have been constructed:
l) Program Bl is used for computation of the grout range, in case when
a bulb is to be made as a result of the injestion,
2) Program B2 is used for computation of the dimensions of a block to be
created by the injection with displacement by another liquid.
The programs also enable the computation of the mean injection rate in the
particular time steps. The printouts of the programs are presented in Appen-
dix A. Figures 58 and 59 illustrate graphically the results of computation of
the programs Bl and B2, for the following data:
^ H = 10 m
R 100 m
r0 = 0.1 m
kw - 5 x 10"4 m/s
n = 0. 1
Coefficient of permeability for the grout (kj changes linearily from 5 x 10"^
m/s for t-0 to 0 for t = tg = 10000 seconds. As an example of the injection
with displacement, the pumping of an additional liquid water had begun after
5000 seconds since beginning of the injection.
Pattern C - The coefficient of the dynamic viscosity of the grout changes
in time and in the aquifer /-i =/J (t, rj for 0
-------
KT3-Q/m r'
B
B
10 t-1000
Fig. 56 Dependence of the radius range r' and the rate
of the injection Q on the duration of the injection t,
for the pattern B ^computation according to the
program B 1 J.
122
-------
10-3-Q/m rB/
[m2/s] Cm]
b
10 t • 1000
O3
Fig. 57 Dependence of the radius range r' of the grout
the radius range of the dilating liquid r and
of the injection rate Q on the duration of the
injection t for the pattern B'(computation according
to the program B 2
123
-------
The situation in the j time step has been presented schematically for
a sector of the injection area figure 58.
•£#•=1 WATERED AREA
GROUTED AREA
Fig. 58 Axial-symmetrical sector of the injection area with
situation in the j*n time step, for the pattern C.
where:
.th
V. - elementary colume of the grout introduced in the j
time step,
whereas: r - .'range of the first portion of the grout in the j time
step, being simultaneously the range of radius of the
grout in the
time step.
For each portion of the grout, there is a different coefficient of permeabi-
lity the characteristic feature of the pattern C depending on the time
during which the grout resides in the soil. It is convenient to assume the
division of the injection duration into equal time steps A. t . For the sym-
bols given on Figure 60, the ranges of pontions being introduced in the j
time step and in the previous steps can be . computed successively. The com-
putation should be commenced from the range of portion of the grout introdu-
ced in the first step:
1 61
A Vj
TTm n
(32)
124
-------
A general formula for the radius range- of the particular portions of the grout,
according to the symbols given on Figure 60 is as follows:
+ r^.-, (33
\ ITmn
for 1 - 1,2, .... f j
Where: rg0~ ^oj where r0 is the radius of feeding well, and for I=j.The ran-
ge of the grout is obtained in the j^h time step. The volume introduced into
the soil in the j^*1 time step is computed according to the following formula:
^V = Q A t (34)
J J
where:
Q4 = 0.5 I Q, , + Q, J 135
._x + Q.)
The rate Q. mentioned in the formula ^35 J is expressed by the following
formula: ^
2TT mA H
(36
where:
k - coefficient of permeability of the grout in the 1 time step.
The formula {36J is valid for eachj = l,2, ..., N provided that the division
of the injection duration has been done with the constant step (A t) .
Due to the fact that it is impossible to compute Q-; directly from the formula
(36) which contains values sought for in each time step, the computation
is carried out by the method of successive approximations ( iteration
method J. In the first approximation (the first iteration ) it is assumed
that Q. = Q. , It enables computation of the first approximation of the
ranges sought for the particular grout portions, and next to compute the
second approximation Q, according to the formula (36). Such a pro-
125
-------
cedure in the iteration cycle leads to achieving the convergence criterion
according to formula (2^. For practical purposes one can assume success'
fully that £=0.001 and such a value has been adopted in the constructed
programs. For the first time step it is assumed Q0 behaves according
to formula(9)
Qj 2TTAH
m
61,
As well as
dj , .
(38j
m
Then the formula(^26 Jwill be simplified to the form of:
r .-=
61 1 TTm
(39)
For simplifying the computation process, the algorithm of the solution
is given in a form of flowchart in Figure 61.
In case of displacement of the grout introduced into the soil previously,
the solution is obtained by applying the above mentioned method, but some
of the given formulas undergo the following modifications:
126
-------
V
DATA
INPUT
1
(= 0
_ _?..TT A H
NO
K_w
C STOP )
Fig, 59. Flowchart of the program C 1.
127
-------
2TTAH
for jNi
L-J-1V2
where:
N - number of the step from which the displacement of the
grout introduced previously begins,
k - coefficient of permeability for the displaceing liquid.
The range of the grout in the j step is determined according to the formula
(39) for 1 = j, while the range of the displaceing liquid is determined
according to the same formula introducing
1 j - N1 + 1 (for j > N
For the pattern C the two programs have been elaborated for computation
on the WANG 2200 minicomputer:
1 Program C 1 is used for computation of the injection radius in case
when a bubl is to be made as a result of the injection,
2 Program C 2 is used for computation of dimensions of the block of a
cylindrical form to be made as a result of the injection with displacement
The programs enable the computation of the mean rate of the injection in the
particular time steps. The printouts of the programs are given in the Appendix
A. Figures 62 and 63 present graphically the results of computation of the
programs C 1 and C 2 for the following data:
A H
R
rc
kv
n
10 m
100 m
0, 1 m
5 x ID'4 m/s
0,1
128
-------
Coefficient of permeability for the grout
5 x ICr5 m/s for
k changes linearily from
t = 0 to 0 for t = tg = 10000 seconds.
In case of the injection with, displacement the water has been used as
the displaceing liquid. The displacement began after 5000 seconds from
the beginning of the injection.
B
10 t • 1000
[s]
Fig. 60 Dependence of the radius range r' of the grout
and the injection rate of the injection duration,
according to the pattern C ( complutation according
to the program C l).
129
-------
Id"3- Q/m rn . r
B
Fig. 61 Dependence of the radius range r' of the grout
the radius range rw of the di'splaceing liquid and
the injection rate on the injection duration
according to the pattern C ( computation according
to the program C 2 ).
130
-------
SECTION XII
LABORATORY INVESTIGATIONS OF GROUTING PROCESS
PURPOSE AND SCOPE OF INVESTIGATIONS
Laboratory investigations of the chemical grouting have been carried out in
application of the isomorphic ground models. The purpose of the investiga-
tions have been the following:
- examining the penetration properties of the grouts during the filtration,
- examining different procedures for introducing the grouts forming va-
rious shapes of stabilized blocks,
« comparing the different values characterizing the injection process re-
corded during the laboratory tests, with the results of computations
carried out according to the mathematical model for the grout flow in
porous medium discussed in Section XL
The realization of the assumed tasks was the condition for measuring satis-
factory results of the field investigations and determining the practical
application of the grouts for soil stabilization. The laboratory tests consis-
ted in pumping the grout through a perforated well and obtaining a radial
dispersion in the porous medium. The injection process was aimed at
obtaineing shapes of stabilized bloks which might be used in engineering have
been investigated (Figure 62) : (ij bulbs piles which could be used in
foundations or in construction of unpermeable curtains, (2) rings for
construction of shafts, galleries, caissons or underground chambers, and
(3J horizontal plates used as bottoms for underground chambers, cais-
sons, etc.
131
-------
3 horizontal plates used as bottoms for underground chambers, cais-
sons, etc.
bulb/pile
ring
horizontal place
Fig. 62. Basic shapes of the stabilized blocks by grouting.
In order to examine the possibility of the injection in different hydrological
formations, various water-soil conditions were simulated during the inves-
tigations. The model investigations for the injections have been studied of
the experiments have been in homogeneous soils, while 2 experiments have
been done in the heterogeneous medium containing layers of different perme<
ability coefficients. A total of 29 experiments have been carried out.
DESCRIPTION OF MODEL INVESTIGATIONS
Model to investigate
The experiments have been conducted by application of a model, as presen-
ted in Figures 63, 64. It consists of a basin in which two perforated cy-
linders have been placed for modeling the soil medium. The basin is used
maintaining an optional water level in the soil. Inside each basin is the injec-
tion well which is used for pumping the grout into the soil. The pumping
pressure has been regulated by the hydrostatic level of liquid in the tank
of the feeding installation.
The basin filled with soil has been used to simulate the hydraulic boundary
conditions in tests with water-bearing soils as well a rational confining of
the investigated zone of the soil. In addition, the basins facilitated the ex-
change of soil, cl'eaning and washing of the blocks.
132
-------
GO
CO
lr
>
r
^
^
1
•>
])
\
k ,
|
I
jrn
1
»
1 . • . -- .- .
1 — 1.: - - '• -• -': '
,•.-••-.•:
=-- * .
I/' /*.-..'.'•••'
3- - .* .- -•- "-
!••- •:•••:-.
i •-: --"."- •
3"
" -• . . - " \
r. -' '-.'-.' • .• _
J*
- * " •-«-
i . • . . " *
i • •
i ' •••'•'•,-
i v- ' ^
i ;--".-•..
i . > - • * •
6
1
p®
\
1
«
»
...:-.--.- -I
• - .". \ • 1
. " •
. • j .' ' • •'
• .' © '-- -\-'l
••- '-.•".- -1
(IT) "" " '1
• . . * " .. " * ' 1
-- . - ~~ i
. ' • • i
-*- . • • -1
"• " '* ' • v 1
^®S -" -'-In
-^ " - - ' I
•' •--- .:'j-(D-
.-..""; • i ©
' ' T — r
J_^. __ ,.- i — j.
1
1
1 ' "
-i . •
' • ' '
3 "
j -• . •
I"/ -\~
r ';:
1 . ; -/
] - -'-:•
3 • .
I, ' '
1 . /
1. . '
1. -
1
i
1 ®
ip
.
*
•
-
»
- -
• - ,
_ - *
• • > •
• - . '-
- * * ••
^. ; f
•' ->-^
- ' _^
' . " —
/ • »
^
f.
L'
,
*
V -.
•
— ; Sr
— c=
— IP
-
50
.
(
-
(
<
-
•
~1
J-d)
. .. -
* . • \
t ~
\ - *.
\ »
2)-.-' -•
. - -. '
^*^ * ' "
"
.' - *
. .
- • • -
2>' •-.:/.
. • • • • -"
• - . • .
'- - • •
-
*
~~~ .
'
•
!
1
u
in
CO
— v j
0
CO
0
r
^~CM
i
1. basin
2. perforated cylinder
3. gate
4. soil
5. water
6. injection well
7. filter
8. inject
9. pressure tank
10. tank
11. pump
Fig. 63. Model for investigation of the grouting
-------
Fig. 64. View of the model for investigation of the grouting.
134
-------
Preparing the soil medium
For modeling the soil media, three types of sand of different permeability
properties have been applied. Depending on the purpose of the experiment.
one type of sand was applied to obtain the homogeneous medium, and tb > -
types to obtain the heterogeneous stratified medium (Figure 65DJ .
In each case, the soil was consolidated by the 5 cm layers, applying always
the same quantity of strokes of a punner. After having filled the basin with
water, the full saturation of the medium has been obtained. The soil zone
destined for the injection under pressure was prepared from an optional
sand, limiting it by ceiling and floor modeled form an impervious foil, and
additionally from clay. As the water level in the basin was above the ceiling
of the soil layer, it was under pressured conditions (Figure 65C J .
The natural conditions of the grout filtration occurred when the water level
in the basin was below the upper boundary of the permeable medium
(Figure 65B) .
Measurement of soil medium properties
Some properties of the sands were determined prior to the model studies.
They were; granulometric and petrographic composition, pH reaction, co-
efficient of permeability as determined in the standard columns. However,
due to the procedure of-preparing the models and the heterogeneity of the
soil, it was necessary to examine, each time, the effective porosity and
water content of sands placed in the basins. To this end, the samples of sand
were taken for determining the effective porosity which appeared nearly
the same and amounted to an average of n =0. 35. The water content of
each particular soils was different. These properties were determined each
time by pumping the same quantity of water V = 4000 cm under the same
pressure HW = 40 cm of head. On the basis of these measurements the
coefficient of permeability has been computed as follows:
"O
0. 366 . Q .log , -,
k = * 12 (41)
m . H
w
After determining the properties of the modeled soil medium, a suitable
mixture of the grout was selected. Its composition depended on the purpose
of each experiment and the required effects of the injection. The quality
of the mixture decided the gelation time as well as grout viscosity changes
in time. Care was always taken to obtain a gelation time longer than the
expected time of pumping the grout, so that it would be possible to pump
in the whole prepared portion. The expected time of pumping the grout was
computed on the basis of the formula 42. Attempts were to have an invariab-
le viscosity of the grout during the time of injection. Each time after having
determined the composition of the mixture , the gelation time and viscosity
135
-------
k -
0.366. Qw, log
(41)
w
B
D
Fig. 65. Models of the soil media to be injected.
changes were examined for the samples. The samples were maintained at
a constant temperature equal to the soil temperature. In the experiments,
the grouts having different gelation times were tested in the range of tg=25
to 300 minutes, density ^ =1.1 G/cm^, concentration of 31 and 42 per-
cent, and the initial viscosities of ,ui = 3. 0-10. 0 cP. The whole portion of
the prepared grout was poured into the auxiliary basin (Figure 63J from
which, gradually, during the injection it was pumped out to the pressure
tank maintaining it at a constant level.
The grout was pumped into the soil from the pressure tank through a perforated
injection pipe. The pumping pressure was determined as a product of the height
of the column of the grout above the water level in the resin and of the grout
density. The pumping caused the penetration of the grout from the pipe into
the soil, and the range of penetration depended upon pressure, pumping time,
viscosity , and on permeability and porosity of the soil. During the experi-
ment the injection rate was examined in order to avoid a local channelization
of the soil. This occurred in the firts experiments and additional sealing plugs
had to be used above the upper edge of the well filter. These plugs had been
installed before applying the grouts of short gelation time. The prevented
breaks occurring in the injection well.
136
-------
Fig. 66. Method for injecting a bulb (pile)
1. pumping of the grout
2. solidified soil
137
-------
Fig. 67. Method for injecting a ring.
1. pumping of the grout
2. area covered by grout
3. ares covered by water
138
-------
Fig. 68. Method for injecting a horizontal plate
1. pumping of the grout
2. pumping of the supporting liquid
3. area covered by supporting liquid
4. area covered by grout
] 39
-------
A bulb was constructed by pumping the grout into the soil and then withdrawing
the injected apparatus. The apparatus was washed with water to enable utilizing
it again (Figure 66) . If the purpose was to construct a ring, the grout was
firts pumped into the ground with the displacing liquid most often water
pumped quickly thereafter through the same filter. The pressure of the displa-
cing liquid caused the translocation of the grout towards the cylinder limiting
the medium (Figure 6?) . Under the proper pressure, this translocation went
on horizontally, parallel to the ceiling and floor of the layer. Under condi-
tions of unco fined flow the grout displaced spatially according to the current
line. The displacing liquid was pumped in the precise quantity necessary for
displacement prior to gelation of the grout. If the purpose of the experiment
was to obtain a horizontal plate, the grouting was carried out by means of
a special tripartite well. This well contained a filter divided into three sec-
tors. Each had a separate joint with its own pressure tank (Figure 68j .
The grout was pumped throught the middle sector. The supporting liquids had
to maintain a flat upper and lower spreading surface for the grout. The applied
supporting liquids were resin withhout hardener, brine and 2 percent solution
of the hydrochloric acid. Both , the grout and the supporting liquids were pum
ped in under the same pressure, albeit the rates of the particular liquids were
different. After injection of all the grout, the pumping of the supporting fluids
also ceased.
After completing each experiment, the injection well was withdrawn and washed
in order to avoid its contamination by the residues of the grout. After 24
hours, the stabilized block was extracted and rinsed with a stream of wa-
ter, to show the real form of the stabilization. Next, the measurements and
photos were taken and the shape of the block was plotted. The volume of the
block \|$ ,the radius rg and the height hg were measured. Simultaneously,
the local deformations were determined and compared with the water-soil con-
dition of the model. The deformation observed served as a basis of correc-
tion of the investigation plan.
ANA LYSIS OF RESULTS
Procedure for conducting the analysis
The laboratory investigations cover a total of 29 successful experiments of
the injection process coverting 9 experiment forming bulbs, 12 rings and
8 forming horizontal plates under laboratory conditions.
Stabilized blocks were obtained as a result of pumping the grout into one in-
jection hole. In the studies all the blocks were of axial-symetrical form.
Thus, determing a form of the block consisted in determining its height which
depended on the length of the filter and the radius of the grouting. This ra-
dius , assuming uniform permeability and porosity of the soil, was found to
depend upon, the pressure magnitude applied to the grout, time of pumping
40
-------
the grout, viscosity of the grout and well radius. The magnitude of applied
pressure was limited by the magnitude of stresses in the soil. During the
injection, disturbance of the soil structure was found to be detrimental to
symmetry of geometric form. With such a limitation for the grout of a de-
termined viscosity, the range of the grouting may be controlled by the
grouting time. Results of the experiments compared laboratory results with
theoretical computed ones. The comparison covered: injection times, volu-
mes of stabilized blocks as well as dimensions of these blocks (radii and
heights} .
Injection time
For the purpose of modeling the injection, it was found to be very important
to determine exactly the pumping time necessary to obtain the radius of the
grouting. The gelation time is determined by the selection of a suitable mix-
ture of the grout. In cases when there is no possibility to examine the form
of the obtained block, the only criterion of correctness of the structure may
be a comparison of the injection time measured under natural conditions with
the computed time.
The injection time for the grouted bulb under the constant pumping pressure
( AH = const) has been computed according to the formula derived in the
Section XI.
"w
'B
The outer and the inner radius of the stabilized block as well as the injec-
tion time for the ring have been compiited by the numerical methods, as for
the pattern B ( Section XI) .
It should be noted that the applied methods for computations refer to the axial
symmetrical cases of the filtration which occur when applying the complete
filter in the pressured layer, or in a length of the filter which is many times
greater than the injection range. In laboratory investigations, during uncon-
fined fiow> short filters were applied more than once, therefore, the isomor-
fic model did not coincide fully with the theoretical one. The injection time
computed as above was comparable with that measured during the experi-
ment .
141
-------
Volume of stabilized block
The projected range of the grouting, the height of the block, the volume of
the bulb and the horizontal plate were computed according to the formula:
(43)
The formula for the ring volume can be expressed as follows:
(44)
, On the basis of the computed block volume of the stabilized soil the quantity
of grout necessary to the pumping has been computed:
n-VB (45)
During the experiments, it was not always possible to pump the projected
quantity of the grout or the water, so the theoretical volumes of blocks were
computed on the basis of the real volumes of the pumped grout or water,
according to the formula:
v = JL
(46)
47)
The computed volumes of blocks and interiors were compared to the res
pective magnitudes of blocks stabilized during investigations on models,
142
-------
The volume of the stabilized blocks were determined by measuring the volu-
me of water superseded by the block submerged in the calibrated vessel.
Assuming that the stabilized block is in a forms a cylinder, the injection
radius for the pumped volume of the grout was computed according to the
formula:
re =
V
7T-n-Lf (48)
In the case of a ring, the theoretical injection range was computed according
to the formula: .
JT • n • L
f
/ N
(49)
Measurement of the injection radius encountered difficulties in some cases
due to formation of irregular block forms. The mean value of r^ was assu-
med to be the calculated cross-section. During unconfined flow the grout
was found to spread out above and below the filter. For these cases, it was
assumed that the computed height of the block was equal to the length of the
injection well filter:
h'B = Lf (50J
The block height measured from the lowest to the highest point was assumed
as the reliable one.
An element frequently used in practice is a bulb (pile) . It is apj.< > - '\ sta-
bilizing foundation construction and underground cuttings, shafts, tunnel, as
well as for building cut-off walls (Figures 62 and 66 ) . In the first series
of the experiments, 9 cases were examined.
They covered:
(a ) one bulb in unwatered soil,
(b) three bulbs in watered soil (unco fined flow) ,
(c) three bulbs in watered soil (confined flow ) ,
(dj two bulbs in watered, stratifield soil (unconfined flow) .
During the experiments, different grout compositions were applied, modifying
the resins by water, glycol or hexamethylene tetramine. The resins were
hardened by oxalic acid or ammonium chloride. The initial viscosity of the
applied resins changed from 3 to 11 cP, while the gelation time ranged from
35 to 250 minutes. Table 25 presents the properties of the grouts used in all
three series.
Table 26 presents a compilation of data concerning methods for the grouting
operation. It should be noted that column 8 gives the mean viscosity moa-
143
-------
sured during the experiment. In some cases, the mean viscosity is different
from the initial one, which refers to the stage obtained immediately after
having mixed the resin with the hardener.
Table 27 presents a compilation of the computed and measured dimensions
of the bulbs. Table 28 contains a comparison of the computed and measured
injections times, volumes, radii and heights of bulbs.
Figures 69 and 70 shows schematically the cross-sections of the bulbs, with
their basic dimensions. The position of the filter is also marked as:
double hatched space. A comparative compilation given in Table 28 enables
estimation of the accuracy of the computation methods.
The ratio of the computed times to the measured ones changes in the range
of 0. 83^^i. <_ 1. 41. Discrepancies result, from difficulties in determining
the coefficient of; permeability "kw , and next, from heterogeneity of the
soil in the model. Similar difficulties will occur under the natural conditions.
On the basis of this series of experiments, computation of injection time, may
be in error by 50 percent.
Comparing the computed and measured volumes indicates that the ratio
VB VB
—— changes for the saturated soils in the range of 0. 75 ^ ^ 1. 54,
B VB
and for the dry soil to 0. 46. In most cases the volumes fit in within the accu-
racy of 10 percent. In experiment 2, the computed volume is greater by
54 percent, than the measured one. This experiment should be treated as
a partial failure, since a considerable spreading of the grout occurred on
the external part of the bulb. The proof was a number of cavities appearing
on the bulb surface. In case of the bulb obtained in the unwatered soil
(experiment 1 ) , the measured volume is twice as large as the computed
one. Investigation revealed that the grout did not fill all the soil pores.
The shape of the bulb and its position in relation to the filter means that the
grout flowed down under the influence of gravity (Figure 7l) .
A comparison of the measured and computed radii of the bulbs
/
0,77 ^ ——
-------
TADJ.K 25. COMPOSITIONS OF GROUTS
Mixture
no.
1
(j
7
8
9
10
11
12
13
14
15
16
17
18
Contents of grout
Type
of
rosin
2
MS-167
MS-167
MS-16T
MS-10
MS-10
MS-10
MS-10
MS-10
MS- 1 0
MS-lSr
MS-lp
MS-10
MS-10
Water
p . o . w .
100 p. u. W.
resin
3
24, 0
25, 0
32, 5
32, 5
45, 0
42, 5
60, 0
42, 5
50, U
50, 0
50, 0
Ethyl ene
glycol
p.o. w.
1UO p. u. w.
resin
4
20
15
5
Urolropin
p . o . w .
100 p. u. w.
resin
5
2, 0
Ammonium
chloride
p. o. w.
100 p.o. w.
resin
6
7,5 •
1, U 1 5,0
3,0 j 10, U
1, 5
1, 5
2, 0
2, 0
0, 5
0, U
L
5, 0
7, 5
6, 7
7, 5
6, 2
6, 2
6, 2
* 1
10% solution
of oxalic acid
_p. o. w.
100 p.o. w.
resin
7
5/0
10, 0
\
45, 0
Initial
viscosity
cP
8
6, 0
7, 0
8, 5
11, 2
4, 5
4, 5
'5, 7
3, 0
4, 5
6, 2
5, 0
5, 0
5, U
Density
G
cm3
9
1, 10
1, 10
1, 10
1, 14
1, 10
1, 10
1, 10
i, ro
i; is
1, 10
1, 10
i.'i'o
.1, 10
MS-10 resin modified by PS /F : M : 1'S = 2, 1 : 1, U : 0, 003/
MS-167 resin modified by PS /F : M : PS = 2, 1 : 1, 0 : 0, 049/
Properties of resins are given in SECTION VI.
-------
TABLE 26. RESULTS OF LABORATORY INVESTIGATIONS BULBS
Types of models: A umvatered soil; B watered soil, unconfined flow; C watered soil, confined flow; D - watered and stratified soil,
uncoiifined flow
Test
no.
1
1
2
3
4
5
6
7
8
9
Model
2
A
B
B
B
C
C
C
D
D
l
Water capacity i Grout
Volume
of
water
Vw
3
cm
3 '
2900
4000
4000
4000
4000
4000
4000
4000
4000
Time of water pumping
tw
h
0
0
0
0
1
0
'o
0
0
m
4
00
07
40
14
50
14
03
02
04
s
48
14
53
49
00
31
06
57
41
Coefficient
of
permeability
kw
cm/s
5
-3
6, 60- 10
1, 24' 10"3
-3
0, 22- 10
0, 66- 10~
0, 24' 10~3
-3
1, 82' 10
8, 54- 10"
-3
7, 05' 10
5, 01- 10~
MixLure
no.
6
12
5
7
ii
14
13
13
13
11
Volume
V
cm3
7
2850
2150
2750
1900
2050
3000
3000
4000
4000
Mean
visco-
sity
cP
8
5, 7
10, 0
14, 2
15,0
6, 0
9, 7
20, 0
3, 0
4, 5
Grouting
Pres-
sure
H
cm
9
80
122
80
100
40
140
235
40
28
Measured
time
- - - - - -
ti
h
0
0
1
0
3
0
1)
0
0
m
10
05
05
42
30
05
11
03
03
10
s
30
00
00
00
00
00
50
45
17
Computed
time
ti
h
0
0
1
0
2
0
0
0
0
m
11
04
07
56
41
29
13
03
03
13
s
36
00
40
27
20
56
28
33
20
146
-------
TABLE 27. DIMENSIONS OE BULBS
Test
n. o.
™
1
1
1
2
3
4
5
6
7
3
9
- - i
Dimensions of
injection well
r
Lenght
f
cm
2
30
30
30
30
28
23
26
30
30
i
Radius
r
o
cm
3
1,5
0,5
0,5
0,5
1,5
1,5
r ~t
Computed
volume
of the
block
V
B
3
cm
4
1
8 140
6 143
7 857
5 423
5 857
3 571
1, 5 3 571
1, 5 11 420
1, 5 11 420
L _ _ _J _ _ _ __
i 1
Measured
volume
of the
block
V
B
3
cm
5
1
17 800
4 000
3 500
5 500
6 000
8 400
11 680
18 000
22 000
r
Computed
injection
range
r'
B
cm
6
10, 03
8, 72
9,36
7, 59
8, 16
16, 12
10,24
-
-
. j
Measured
injection
range
r
cm
7
13, 0
8,5
13, 5
7,5
8, 5
10,0
12, 0
L
Real
height
of the
block
h
B
_
cm
8
40
25
41
•
41
28
23
26
30
30
-------
TABLE 28. COMPARATIVE COEFFICIENTS OF INJECTION TIMES
AND BULBS DIMENSIONS
Test
no.
•-
_».-. — . - _ _ _ -^
1
1
2
3
4
5
6
7
8
9
*'i
I
i
— ----------
—
2
0, 84
1, 40
1, 14
1, 38
0, 81
1, 26
0, 91
0, 94
1,29
V/B
VB
- 1
3
1, 46
1, 53
0, 92
0, 99
0, 98
1. 02
0, 74
U, 63
0, 52
L
r/B
•rB
"
4
0, 77
1, 02
0, 73
1, 01
0, 96
1, 61
0,85
-
.- .
h/B Lf
HB hB
-
5
0, 75
1, 20
0, 73
0, 73
1, 00
1,00
1, 00
1, 00
1, 00
L ,
048
-------
Jr3s.
17
15
25
o
12
(7
^ i4 i
Fig. 69. Cross-sections of the bulbs obtained in the tests 1-6,
149
-------
o
to
J L
8
Fig. 70. Cross-sections of the bulbs obtained in the tests 7-9.
150
-------
1
Fig. 71. Bulb obtained in unsaturated soil ( tests l) .
15]
-------
plugging affects the filter in the obvious manner, of producing irregular stabi-
lized blocks. The bulbs obtained in the heterogenous sands proved that the
injection range depends upon the permeability of the layers.
In both experiments 8 and 9, grout flowing down into lower part of the per-
meable layer was observed. This was caused by binding time being considerab-
le greater than the pumping time of the grout.
These experiments proved the possibility of these grout compositions for
obtaining bulbs (piles) . The experimental results confirmed the accuracy of
the theoretical analysis (Section XI) . In practice, in most tests, length ot
the bulb is multiples greater than the diameter. In this situation the presen-
ted theoretical scheme of the radial flow will be closer to the real one than
that which occurred during model investigations, where short filters were
applied. Due to the difficulties in determining the exact coefficient of permea-
bility, and due to a possibility of heterogeneity, the computed injection times
should be increased by 50 percent. Due to the possibility of spreading grout
in the frontal zone, the grout volume should be computed with some reserve.
It is estimated that such a reserve should amount to approximate 10 percent.
Forming rings with soil and grout leaves unstabilized soil inside the streng-
thened structure thereby decreasing the quantity of the applied grout, and
enabling the reduction of the costs. Investigations of the ring series included
studies of seven rings during unconfined grout flow and five rings during
confined grout flow.
Table 29 gives the compilation of the data for the laboratory investigations,
Unlike Table 26, Table 29 contains data regarding the grout dilution by water
or by brine. In the experiments 14, 15 and 16, the salt solution of a density
equal to the density of the grout y =1.10 ^ ^ has been applied as
the diluting liquid. Cll>
Table 30 shows the compilation of the computed and measured dimensions of
the rings. The comparison of the computed and measured results are given
in Table 31. The columns show the relations of the computed magnitudes to
the measured ones. In column 4, the computed volumes of the ring interior
have been compared to the measured ones. The ring interior has been compu-
ted on the basis of geometrical dimensions. When comparing the radii, the
external radius of the ring has been taken into consideration. Schematic cross
sections of the blocks obtained in the experiments 10-21 are shown in Figu-
res 74, 75.
Comparing the ration of the computed and measured times, we see that of
the 12 cases, 8 of the values were 0. 89 < ti < 1.27.
t' % t- ^
17, the ratio was i _ 1. 69. l
In experiment
152
-------
Fig. 72. Cross-section of the bulb obtained during unconfined grout
flow (test 3) .
153
-------
Fig. 73. Bulb
obtained during confined grout flow (test l)
154
-------
TABLE 29. RESULTS OF LABOHATOKY INVESTIGATIONS - RINGS
§
tfl
0)
1
10
11
12
13
14
15
16
17
18
19
20
21
-u
o
g
2y
B
"
"
"
"
11
"
c
"
"
"
11
Water capacity
Volum
of
water
V
w
3
cm
3
4000
4000
4000
4000
4000
4000
4000
4000
4000
4000
4000
4000
° t
h
t
w
m
4
03
07
06
06
06
13
12
48
21
58
18
15
s
32
26
04
04
59
00
40
33
33
34.
27
59
^ 3
'o rt
S° g
8 I
w
cm/s
1 5
-3
10, 18- 10
5, 59- lo"3
4, 85- 10~3
4, 85' 10~3
3, 49- 10"3
1, 78- 10r3
1, 6~ '.0~3
0, 50- 10
1,41' 10"3
0, 42' 10~3
1, 42- 10"3
1, 42. 10~3
Grout
o
Mixture i
6
8
8
9
g
9
9
9
11
11
12
12
12
Volume
V,
•3
crei
7
4000
4000
4000
4000
4000
4000
3700
3000
3000
3000
3000
3000
Mean
viscosit^
cP
3
4, 5
4, 5
11,2
11, 2
11, 2
11, 2
11, 2
4, 5
4, 5
(i, 0
4, 5
4, 5
QJ
Pressur
1 CrouLuiK
•a
in p
d 'Jj
L
T' 'i
cm 'i
9
11 O!
•1C
4U|
R 0,
81
St
111
!H
ill
•U
•II
•1 1
1
1
m
10
14
13
21
47
22
30
10
52
30
41
36
25
j
6
17
03
15
03
00
00
00
00
00
25
50
40
T3
II
b
U
^
h
1
1
----
m
11
05
16
27
13
19
35
41
22
25
45
43
32
s
09
40
40
40
00
30
00
HO
40
(JO
40
05
Dilation
QJ
Pressur
»w
cm
12
80
80
80
10
5
5
200
80
80
40
80
80
P
u-, cr
Volume o
dilating li
c
3
cm
~~
13
4000
4000
4000
4000
4000
4000
4000
8000
3000
400
3000
4000
VH 60
C T)
OJ 'K -^<
ft -3 °<
H 3 3
14
water
"
11
11
w. H-NaCl
"
M
water
M
"
11
11
J
II
'c
m
4
6
11
37
15
15
10
50
21
10
11
16
s
15
35
10
00
20
00
00
00
00
30
30
03
00
U55
-------
TABLE 30. DIMENSIONS OF RINGS
-- - T -- ~r -- T- - ~- 1
Test
no.
1
—
—
1
10
11
12
13
14
15
16
17
18
19
20
21
i
i
i
Dimensions of
injection well
L,enght
L
f ,
cm
2
— J
30
30
30
30
30
30
30
21
24
30
28
25"
i
Radius
r
o
— _ .j
cm
1
3
0,5
0,5
1,0
1,0
1,0
1,0
1,0
i, o
1,0
i, o
i, o
1, o'
Computed
volume
of
petrified
block
r
V'
B
_____
cm
r
4
11 43Q
11 430
II 430
11 430
11 430
11 430
10 573
3 571
3 571
3 571
8 571
8 57T
i
i
Measured
volume
of
petrified
block
V
B
" |
3
cm
5
12" 000
II 900
27 000
" 21 000
18 500
17 000
18 500
9 500
3 500
1 142
15 500
15 120
Computed
volume
of the
dilated
block
interior
V'
c -
3
cm
6
_
-
11 430
11 430
11 430
11 430
11 430
8 571
3 571
I Quo
3"~571
11 430
r
T 1
Measu-
red volu-
me of
the dila-
ted block
interior
V
C
3
cm0
_ _.
7
-
4 QUO
4 000
4 OOu
4 OuU
5 000
4 500
10 OOu
1 QUO
7 000
9 940
i - j _ ' _ _ ^ J. - -• ^
Compu-
. ted in-
jection
range
r'
B
1
cm
8
-
16, 82
1 6, 82
16, 82
16, 82
16,50
16, 12
'-5, 07
14, 56
13, 96
15, 96
Measu-
red in-
jection
range
r
B
cm
-
9
- — — i
-
17, a
16, 5
15, 0
18, u
17,0
17,0
16,7
13, 0
16, 0
16,7
- - 1
Real
height
of
block
h
B
era
10
48
48
44
53
43
21
24
24
25
25
^ ! j
-------
H
'.5
Fig. 74. Cross-sections'of the rings obtained in the tests 10-15.
157
-------
& L _
S-\
-I
:0
U—"? ,
V_i^U
i V
<1
O '
-------
This discrepancy may be explained by the fact a part of the grout has run out
beyond the pressured layer, thus decreasing the injection time. In the expe-
riments 10, 12 and 13 the computed times were considerably shorter than
those determined during the experiments. It resulted from different technical
difficultues occurring in the model investigations. These results should not
be taken into consideration when a summary analysis is being done. One can
draw a general conclusion that the computed times are, approximately, consis-
tent with the measured ones.
The comparison of the volumes of the stabilized blocks indicates that
v'
0.42 <^ — : — <^ 1.07. In three cases this ratio is close to 1.0 (experi-
B
ments 17, 18 and 19) . In all the experiments in which the grout of the 42
percent concentration has been applied (experiments 12, 13, 14, 15 and 16),
the measured volume is considerably greater than the computed one. It was
found that the concentrated grout being diluted, undergoes the dilution itself,
thus increasing the volume of the stabilized soil. In those experiments in
which the volumes of blocks increased, the volumes of their interiors decrea-
sed (Table 31 j . The ratio of the sum of the computed and measured volumes
of the stabilized and the diluted soil changes in the range of
V' + V'
0.74 / P V_ / 1. 22. This means that the diluting water constitutes
< VB+ vc <
a component of the grout stabilizing the soil.
The ratio of the computed and measured length of the external radii varies
/
r
by o 87 / ^ /" !• 12, whereas the ratio of the heights changes in the
"~
range of 0. 57 / B S lt25-
< ~<
The cross-sections of the stabilized blocks plotted in Figures 74 and 75 show
these differences. As one can see from the cross -sections, the grout has
flowed down to the bottom of model in the experiments 10 and 11. It was cau-
sed by too long gelation time in relation to the injection time. In the experi-
ment 13, the ring has been displaced in upper part of the block, while in the
experiments 14 and 1 5 in the lower part. The most successful, under the
conditions of unconfined flow, should be considered experiment 12, during
which the block has been displaced by water. Experiments 17-21 carried out
under the pressured conditions of the filt rations may be considered as
successful ones, since the obtained block shapes are close to the foreseen
cylindrical shape.
These investigations have demonstrated the possibility of obtaining stabilized
soil block of the ring shape, through pumping the grout and next displacing it
159
-------
TABLE 31. COMPARATIVE COEFFICIENTS OF INJECTION TIMES
AND RINGS DIMENSIONS
Test
no»
-
1
10
11
12
13
14
15
16
1.7
18
19
20
21
t'
t .
i
2
0, 46
1, 24
0, 61
0, 31
0, 93
1, 27
0, 55
1, 69
0, 89
1, 04
1, 18
1, 25
V'B
VB
-
3
0, 95
0, 96
0, 42
0, 54
0, 62
0, 67
0..57
0, 90
1, 01
1,07
0, 55
0, 57
v'c
vc
-
- « -. _>
4
- - - — - - -
-
2, 86
2, 84
2, 86
2, 86
2, 86
1, 90
0, 86
1, 14
1, 22
1, 21
_. j
r'
rB
-
5
.
0, 99
1, 02
1,12'
0, 93
0, 97
0, 95
0, 90
1, 12
0, 87
0, 96
h' B _ Lf
hB hB
-
.
-
0, 62
0, 62
0, 68
0, 57
0, 70
1, 00
1, 00
1, 25
1, 12
1, 00
_____._.., a
v' v'
V. B + C
V + V
B C
-
7
-
0, 74
0, 91
1, 02
1, 0!)
0, 96
1,22 '
0, 93
1,07
0, 76
0. 81
160
-------
Fig. 76. Cross-section of the ring obtained during unconfinecl grout
flow (test 12)
161
-------
Fig. 77. Ring obtained during confined grout flow (test 17j .
1 62
-------
Fig. 78. Ring obtained during confined grout flow (test 17 )
163
-------
Fig. 79. Ring obtained during confined grout flow (test 20)
164
-------
by water from the same hole. The model investigations confirmed the prog-
noses made by means of computations. However, the influence of accidental
factors, such as perforation of the grout layer by the displacing liquid and
a change of the block shape due to the soil heterogeneity should be -taken
into account. Displacement the grout by water causes its partial wa
ce a part of the grout stays in the soil pores entering into the reactu'<
the displacing water. It may cause an unfavourable change of parameters of
the stabilized soil. This should be taken into consideration when selecting
the suitable grout compositions.
In the horizontal plate series, eight experiments have been carried out.
Table 32 presents data regarding the process of the experiments. In expe-
riment 22 the grout was pumped only through upper part of the filter.
The resin without hardener was pumped through two lower parts. In this case
the resin was used as the supporting liquid only. In the experiments the resin
was applied to avoid the grout washout by the supporting liquid.
Because the resin had the same density as the grout, it was expected this
would lessen the downward flow of the grout. In experiment 23 the grout was
pumped through the central part of the filter while the supporting liquid was
passed through only the lower part. This caused the penetration of the grout
into the empty upper part and into the soil, thus creating the b}ock of the form
showed in 'Figure 80. In the remaining experiments 24-29, the grout was
pumped through the central part of the filter, while the supporting liquid
flowed through upper and lower parts. The brine of the density of the grout
was applied in these experiments. The solution of the hydrochloric acid was
used in the experiments 28 and 29. The purpose of this was to cause a rapid
gelation of the grout on the boundary grout solution, thereby creating the limi-
tation for spreading the grout.
The computed and measured volumes of the horizontal plate, radii, and thick-
nesses have been presented in Table 33. Additionally, the following indices
characterizing the block shape have been given: the ratio of the block volume
to its radius, according to measurements and computations
/ V'
. a _ B as well as the rations of radius and lengths to
rB
rP r/
plate thicknesses h - . • b' _ B
-~
To Table 34 the comparison of the computed and measured results has been
presented. The comparison of the volumes gives the following values •
V'
0,41 / B / 1.03. This means > that the volumes of the stabilized
< VB <
block are, almost in all cases, greater than those computed on the basis oi
165
-------
TABLE 32. RESULTS OF LABORATORY INVESTIGATIONS - HORIZONTAL PLATES
Test
no.
1
22
23
24 ~
25
26
27
' 28
29
'•-..
Lenght of injection
veil
Upper
part
Lf
cm
2
16
16
16
16
16
I
.16
16
Middle
part
Lf
cm
3
8-
8'
8
8
.8
8
8
8
Lower
part
L
f
cm
4
16
16
16
16
16
16
16
16
—
Type
of
liquid
5
grout
resin
resin
resin
water +
NaCl
water +
NaCl
water +
NaCl
r _UPP_
Pres-
sure
H
cm
6
60
70
70
70
60
57
57
Volume
V
3 n
cm
7
5000
8000
5000
9000
22000
7500
6500
Time
t
S
8
3000
3600 .
3600
3600
2700
2700
2400
'Rate of
1 cm
filter
lenght
q
cm /s
S
0, 104
0, 138
0, 080 .
0, 156
0, 509
0, IT'S
0, 302
^routing
Type
of
liquit]
10
resin
grout
grout
grout
grout
grout
grout
grout
Pres-
sure
H
cm
11
60
70
70
70
70
60
50
50
Volume
V
3
cm
12
6600
5000
6000
8000
3000
2900
2300
3250
Time
t
S
13
300U
3600
3600
3600
3600
2700
2700
2400
Rate of
1 cm
filter
lenght
q
2 .
cm /s
14
0, 270
0, 208
0, 208
U, 277
0, 104
0, 134 '
0, 106
0 353
Type
of
liquid
15
resin
resin
resin
resin
resin
water +
NaCl
water +
NaCl
water -I-
NaCl
I
Pres-
sure
H
cm
16
60
. 70
70
70
70
60
57
57
jower nart
Volume
V
"""cm3"""1
17
3400
15000
40UO
8000
7000
22000
7500
6500
Time
- - -
I
S
18
3000
3600
3600
3600
3600
2700
2700 '
2400
Rate of
1 cm
filter
lenght
q
cm /s
19
0, 270
0, 312
0, 068
0, 138
0, 121
0 509
0 173
0 302
-------
22
23
24
26
Fig. 80. Cross-sections of the horizontal plates obtained in the
tests 22-27.
167
-------
28
29
Fig. 81. Cross sections of the horizontal plates obtained in the
tests 28-29.
68
-------
TABLE 33. DIMENSIONS OF HORIZONTAL PLATES
o
C!
B
i
22
23
24
25
26
27
28
29
"O
"3 -g
u ^
h'
B
cm
2
16
8
8
8
8
8
8
8
5 ""'
§ ^
h
B
cm
3
16
23
14
23
23
12
13, 5
9, 0
-a
S 0)
g. s
fi 3
o 1
u >
V
B
3
cm
4
14 :i;,"
14 286
17 143
22 857
8 571
8 286
6 571
9 286
-o
I S
s
V
B
3
cm
5
20 000
14 500
42 000
46 000
27 OUU
17 600
9 600
9 UOO
Q, bD
S ^
O [,
O
B
cm
6
16, 9
23, 8
26, 1
3U,2
18, 5
111, 2
16, 2
19, 2
' ,
i j
-' ,i
1!
i in
I
-d, 5
U, 0
'Mi. U
oil, U
'"."
'.'U, (1
19,5
21.5
v
' It
.i
1:111
11
U70
;uo
1-100
I 5 3 0
I :i.ill
liau
40
410
480
r
B
hB
b
10
1.28
0, 78
2, 14
1, 07
0, 80
1, (ili
1, 44
2, 38 ..
•
r B '
hB
b'
11
1, 05
2, 97
3,26
3, 77
2, 31
2, 27 ;
2, 02
2, 40
-------
TABLE 34, COMPARATIVE COEFFICIENTS OF DIMENSIONS OF
HORIZONTAL PLATES
T,-,r.4-
i est
no,
-
1
22
23
24
25
26
27
28
29
i-.--._ .
_
V'
r>
VD
2
pj-.^---*---
0, 71
0, 99
0, 41
U, 50
0, 32
0,47
0, 68
1, 03
u._
r'
r>
rB
3
0, 82
1, 32
0,87
1, 00
0, 93
0, 91
1, 20
0, 89
h'
B
"B
-
__-___--_-^«._
4
------ — I.----
1, 00
0, 34
0, 66
0, 28
0, 34
0, 66
0,59
0, 88
"•-""
a'
a
-
_.......-_-._.., —
5
0, 86
0, 74
0, 47
0, 49
0, 34
0, 51
0, 83
1,17
L-, u
r 1
b'
|,
n
6
1,17
3, BO
1, 52
3, 52
2, 68
1,36
1, 40
1, 00
__.
1-70
-------
the grout quantity and the soil porosity. This can be explained by mixing of
the grout with the supporting liquid.
The ratio of the computed and measured radii changes in the range from
r'
0,82 / B_ / 1,32, while the ratios of the heights thicknesses amount
Vi '
to 0. 28 / B /!_(). As can be seen, the values of the measured radii cor-
hB
respond, approximately, to those computed. However, the thickness of plates
has changed considerably, as is reflected by the ratios -§- and -g— .
Analyzing the shapes of the plates ^Figures 80 and 81 j one can consider three
experiments (22, 28 and 29J as fully successful. The most successful is the
experiment 29, which the ratio rB - 2. 37.
rB
In experiment 25, after having completed the pumping of the grout, the additio-
nal 1000 cm3 of water has been pumped for the purpose of ringing the filter. It
caused displacement of the grout and creating of the ring. In experiment 27,
in the first phase of pumping, the pressure of the grout was greater than that
of the supporting liquid. It caused the creating of a spherical bulb, which after
having adjusted the pressures, has been lifted on the outside, as it is shown
in Figure 80. In the experiment 24, the grout has flowed in the vicinity of
the outer walls of model as a result of excessive gelation time.
The investigations of the III series proved the possibility of making relatively
thin horizontal plates from one grouting hole. A supporting liquid should be
pumped above and under the grouting plate being formed. To obtain successful
results, the same pressures should be maintained on the grout and supporting
liquids during pumping. The best results (experiments 28 and 29J were obtai-
ned by applying, as the supporting liquid, the solution of the hydrochloric acid
which accelerates the gelation on the surface confining the spreading of the
grout.
- 171 -
-------
Fig. 82. Horizontal plate obtained in the test 28.
- 172 -
-------
Fig. 83. Horizontal plate obtained in the test 28.
- . 173
-------
29
Fig. 84. Horizontal plate obtained in the test 29.
- 174 -
-------
SECTION XIII
FIELD INVESTIGATIONS
PURPOSE AND SCOPE OF INVESTIGATIONS
Field investigations were conducted to examine application of the stabilized
foundation under natural conditions . Special attention was paid to the methods
for constructing and sealing the injection wells, selection of the grout com-
position, selection of the grouting equipment, possibilities of installing verti-
cal curtains.
The field investigations were carried out on the experimental ground at Rynia,
near the Zegrze river reservoir. The soils of the experimental ground con-
sisted of medium sand of a considerable thickness . Location in the vicinity
of a great river reservoir assured a constant level of ground water . Topog-
raphy of the area allowed investigations both in watered and unwaterecl
soils .
Before proceeding with the grouting, the following parameters were determi-
ned : depth of water table below the ground surface, air temperature in the
well at the injection depth assuming that it is equal to the soil temperature
and moisture capacity of the soil. For determining the moisture capacity,
a fixed quantity of water was pumped into the hole (80 or 100 litresj while
measuring simultaneously the pressure and pumping time. The pressure
value was assumed the same as that of the grout pumping (Tables 35 and 36)
The laboratory investigations of the soil samples examined proved that the
soils on the experimental ground are characterized by a great homogeneity.
In this connection, the effective porosity was assumed as constant n =0.35.
DESCRIPTION OF FIELD INVESTIGATIONS
Two methods for constructing the injection well were applied in the experi-
ments : driving the well by the vibrating hammer (Figure 85J and by jetting
the well in the casing pipe (Figure 86) .
Driving the well by the vibrating hammer were applied in the experiments
T1-T5 and in T17-T20. In all the remaining experiments the method of
installing the wells was by jetting.
175
-------
1 vibrating hammer
2. three - footed table
3. injection well
Fig. 85 Vibrohammering the injection well
••'•0\ I 1 I '
;A'ww,vv*wv.^ww«'Ailw*w.*^
-------
The method of jetting proved better for these soils rather than driving the
well. Driving the well by means of vibration resulted in a greater diame-
ter of the hole in the unsaturated soil than that for the pipe. Under such
conditions the grout penetrates to the chink between the pipe and the soil,
thus increasing the active length of the filter and creating channels for
flow of the grout to the soil surface. In the soils situated below the water
table, the sand clung closely to the well hole. In watered and unwatered
soils, fissures may remain. In field investigations the chink was filled
up with sand . To obtain better effects, great quantities of water were
poured into the chink to produce the results similar to those in the satu-
rated soil. In some experiments (for example T4J , the well was dug up
to the upper edge of the filter (0.4m below the ground surface) , and next, by
layer, the soil was compacted exactly by the punner . Thus, a good sea-
ling has been obtained, but this procedure takes much time and is difficult
for application with a filter of great depth.
The method of jetting the injection well gave good results both in watered
and unwatered soils because it caused the self-sealing of the well with
the sand saturated by water pumped during the jetting operation. However,
with a great pumping of the grout, there is a possibility of hydraulic bre-
aking of the soil along the shortest way of pressure relief. To avoid
this, the ground surface was sealed around the well with grout after dri-
ving the well (Figure 87j . This Figure presents a scheme of the grout
penetration, where there is a fissure around the well, in the over - and
under - filtrated zone .
P.T
I
1 seal
2 . filter
3 . penetration zone
4 . fissure
Fig. 87 Surface sealing for the grouting
in unsaturated soils
177
-------
Care must be exercised in applying pressures to prevent blowing off the
seal (l) - This actually happened in experiments T6, T7 and Til. A good
joint of the seal with the injection well is necessary. In experiments T8
and T16 the sealing was performed from the grout having a gelation time
of three hours . There was no outflow during the grouting .
Two different sets of equipment were used in the field investigations . Set no .
1 is presented in Figure 88. It consists of the grouting tank of 100 liters
volume. The tank is placed on the platform, the height of which can be
changed depending upon the required pressure of pumping . The grouting
tank is joined by an elastic hose with the well end standing above the ground
surface. Tanks for resin and for hardener are placed separately upon the
ground . The grout components are pumped into the grouting tank where they
are mixed together . In the set no . 2 (Figure 89J a pump for pumping the
grout under the determined pressure has been used. The suction side of
the pump hose was immersed in the grouting tank to which the grout com-
ponents were fed by gravity from resin and hardener tanks . A reducing
valve was located at the outlet of the pump for pressure control. The in-
jection wells were prepared from perforated parts of pipes of 0.5 or 1 .5m
length as well as from unperforated pipes joined with filter parts with
length of 1.0m. It enabled the suitable constructions of the wells under
various water soil conditions .
Knowing the parameters of the soil, the following data were computed: the
volume of the grout for a block of the required dimensions the expected
height and radius of the block, and an approximate time of pumping for the
assumed pumping pressure and the grout viscosity. On this basis a suitable
composition of the grout, with the required gelation time was selected .
After some initial experiments, it was learned that a number of unexpected
circumstances should be taken into consideration, since they may cause an
interruption during the grout pumping. Too short a gelation time may cause
binding of the grout before introducing the whole quantity into the ground .
For these studies, the gelation time was adjusted with a great time reserve,
for instance, for 30 minutes of pumping, the gelation time of 150 minutes
was used . During the experiments the grout concentration was adjusted so
that the viscosity would be the lowest possible . In all the experiments the
viscosity amounted to approximately ScP,.--, The composition of the grout
is presented in Table 25 .
The grout was pumped into the soil by increments . This procedure became
necessary because the air temperature was higher than the soil tempera-
ture resulting in quicker gelation of the grout. During the field tests, grout
components were mixed only after having pumped the precedent portion.
The volume of each portion was determined under assumption that it cannot
stay in the injection tank longer than 2/3 of the gelation time . In this way
178
-------
the viscosity of the grout pumped into the soil amounted to M1 = 5cP, thus
enabling the application of the pattern A (Section Xl) for computation
of the injection times .
Grout was injected into the soil, followed by application of water through
the same well. The purpose was to obtain a ring structure. The water
was poured into the empty grouting tank, and next pumped into the soil
under the determined pressure.
Thirty-four (34J experiments were attempted, of which 16 were in unsa-
turated soil (Tl-Tie) ., and 18 in saturated soil (T17-T34) . Thirty-two
(_32) bulbs and 2 rings were made. Five (s) blocks (T1-T5J were cons-
tructed as single blocks. Eleven (ll) bulbs were constructed to form
a vertical curtin (T6-T16) . Eighteen (is) bulbs (T17-T34) were joined
together in such manner that they formed a basin, of which 12 bulbs (T17-
T28) constituted the horizontal walls, and 6 bulbs (T29-T34) the bottom
plate .
The investigations on aging of the grout were conducted, as described in the
Section VIII, on the blocks on the experimental ground .
The first four experiments (T1-T4J cover the single bulbs. All data concer-
ning the grouting procedures are given in Table 35 . The Table contains
data regarding the applied grout mixture numbers of compositions accor-
ding to Table 25, soil conditions, well dimensions, method for driving and
sealing the well and procedure for the grouting . In the last column, the
ratio of the computed time (ti) according to the Section XI, to the measu-
red one (ti) has been given. In all the experiments the short filters of
0.5m length were used. They were inserted in a way that upper edge of
the filter was 0.5m below the ground surface. The wells were driven by
means of a vibration hammer. In experiment T4, the additional compaction
of the soil layer above the filter was accomplished . The shapes of bulbs
are shown in drawings (Figures 90 and 92j as well as in photos (Figures
91 and 93) . These Figures demonstrate clearly the influence of the
soil compaction in the vicinity of the pipe above the filter on the bulb shape
Due to the lack of compaction experiment T1-T3 , a deformation of the
bulb occurred, caused by the grout penetrating along the pipe. It did not
occur when the soil was compacted (Figure 92j . The results of the field
investigations coincide very well with those of the laboratory investigations .
It is worth noting that in the field investigations, that the bulbs had almost
ideal axial symmetry. This was due to the homogeneity of sands .
The comparison of the computed times with those measured indicates
that 0.55 <^ _ - _ ^ 0.93. During grouting, air accumulation occurred
and stopped the pumps resulting in a much more variable ti . In spite of
179
-------
1 . mixer
2 . tank for resin
3. tank for hardener
4 . platform
5 . seal
6 . injection well
Fig . 88 Set 1 of the grouting equipment
©
rJs^W^ft'&AkJ'i'
-*—
t
]=*
7'-Wi
1
c
_l
~f M-
~^ _l
CO
\ r .1 ....... i f,~— — ' Ij
^=$?hh -^ "xT
I Cz] ^ — ^^~"
1 . injection pump
2 . mixer
3 . tank for resin
4. tank for hardener
5 . valve and manometer
6 . injection well
7 . seal
Fig.89 Set 2 of the grouting equipment
180
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
1 . real shape
2 . theoretical shape
Fig .90 Cross- section of the bulb
injected in unsaturated
soil (tests T 1 T
182
-------
T1 T3
Fig.91 The bulb injected in unsaturated soil (tests Tl - T3j
183
-------
1 . real shape
2 . theoretical shape
3 . consolidated soil
Fig.92 Cross-section of the bulb
injected in unsaturated
soil (test T4)
184
-------
T4
Fig.93 The bulb injected in unsaturated soil
(test T4) .
185
-------
P.T.
Fig.94 Cross-section of the ring
injected in unsaturated soil
(test T5 ) .
186
-------
T5
Fig.95 The ring injected in unsaturated soil
(test T 5) .
187
-------
Fig.96 Cross-section of the ring injected
in unsaturated soil (test T 15 J .
188
-------
Fig.97 The ring injected in unsaturated
soil (test T is) .
189
-------
this difference the results of the experiments should be considered as fully
satisfactory. The results support the conclusion drawn on the basis of the
laboratory investigations that the projected injection time should contain
a considerable reserve in comparison with the computed time . This allows
coping with unforeseen difficulties which may occur during the grouting
under natural conditions .
In the experiment T5, a single ring has been formed . Ninety (90J litres
of grout and 80 litres of water were used . The block shape is illustrated
in (Figure 94J and in photo (Figure 95 j . The result of the field in-
vestigations coincides closely with the results of the investigations in Sec-
tion XII - experiment 16. In each case a typical bulb diluted with water
has been obtained . Such a bulb is formed when the block radius is relati-
vely great in comparison with filter length. In experiment 15, the ring
was by means of 1.5m filter (^Figures 96 and 97J . The field investiga-
tions verified the possibility of forming a ring from one injection hole-
Construction of a vertical curtain was attempted by joining 10 piles bulbs
and 1 ring (Figure 98 j . The curtain was made in the shape of a horseshoe
to enable digging it up from one side. The data regarding the grouting in
the particular holes have been compiled in Table 35 . One and one-half
(l.5 my filtres were used in all the wells with upper edge being 0.6m
below the ground surface. Experiments T10 and Til should be considered
as unsuccessful, since in experiments T10 and the injection was stopped
due to clogging of the filter, and in experiment Til the grout flowed up
the filter pipe in spite of the seal. The grouting of the remaining bulbs fol-
lowed expectations . The ratio of the computed and measured times changed
in the range of
1.35. Extending the real injection time was necessary
due to the increase of resistance of penetrations in the vicinity of the exis-
ting stabilized soil blocks . After partially uncovering the curtain from one
side, it was revealed that, in almost all the cases, the grout flowed upward
to the surface sealing, creating irregular cones. As the depth increases,
the diameters of the stabilized blocks increase and their volumes, in all
cases, prove to be greater than the planned ones. The uncovered curtain
has been shown schematically in (Figure 99J and in photos in (Figures 100
and lOl). The blocks were excavated and washed by means of a strong
water jet. Inspection revealed blocks T6, T7, T8, T9,T15, and T16 to
form compact monoliths one to one and one-half \1 1 .5j meters below
the ground. Block T10 was connected to adjacent blocks only on the lower
portions .
190
-------
CD
Fig .98 Location of the blocks in vertical curtain
-------
pj. T6
Fig.99 Cross-section of the vertical curtain
192
-------
*T6TI4
Fig. 100 A part of the vertical curtain (tests T 6 - T 14)
193
-------
T10T16
Fig. 101 A pant of the vertical curtain (tests T10, T15, Tie)
194
-------
0.8rn
Fig. 102 Scheme of the basin
195
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
. 1 . real shape
2 . theoretical shape
3 . seal
4. groundwater level
Fig .103 Cross-section of the blocks obtained
in the tests T17 - T20
(vibrohammered injection wellj
197
-------
P.T.
1 . real shape
2 . theoretical shape
3 . seal
4 . groimdwater level
Fig. 104 Cross-section of the blocks
obtained in the tests T 21 - T 28
(the jetted injection welly
198
-------
The experiments have proved the possibility of forming continuous, verti-
cal curtains . It should be noticed however, that the continuity of the curtain
can only be obtained on 1.0m depths and lower in subsurface. Above this
depth voids occurred which were undesireable for the purpose of this
study.
Studies on grouting below the ground water surface revealed stabilized
objects, such as a basin, could be made. One is shown in Figure 102
having an external diameter of 3.80m, bottom level approximately 0.70m
below ground surface, and 0.20m below ground water level. All the para-
meters characterizing these experiments are given in Tabele 36 . In Figure
103 the shape of blocks formed by means of driving the filters T 17 T 20
is shown schematically. Figure 104 illustrates the shape of blocks created
by jetting the filters (T21-T28J . The blocks forming the basin have been
retained in place for studies on aging of the grout in saturated soil conditions.
Field investigations of injection grouting clearly indicated the possibility
of soil stabilization in the subsurface saturated zones .
199
-------
SECTION XIV
REFERENCES
1 . R6g, S., A .Juraszek. Wybrane zagadnienia ochrony 6rodowiska natu-
ralnego cziowieka /Selected Problems of the Environmental Protection/.
Sprawozdanie dla IMGW, Warszawa, 1973.
2. Prospekt. Injektionsmittel AM-9, Am.Cyanamid Co, 1968.
3. Technical Date Scheet. Halliburton Pressure Grouting Service, Halli-
burton Co .
4. Goncharova, L.V., R .S .Ziangirov . Opyt sozdaniya prochnykh protivfil-
trationnykh ekranov iz peskov ukreplennykh krabamidnoy smoloy
/Studies on Durable Counterfiltration Curtains of Sands Strengthened
by Carbamide Resin/. Vestnik Moskovskogo Universiteta . Seriya TV -
Geologiya, No 6:65-79, 1965.
5. Goncharova, L.V.Osnovy isskustvennogo uplotnenya gruntov /Foun-
dations of Artificial Soil Hardening/. Izdat M ,G .U . Moskva, 1972 .
6. MMkowski, W.,E.Gliwa. Zastosowanie Iignochrom6w do stabilizowa-
nia g6rotworu /Application of Lignochromes to Stabilization of Geologic
Formation/. PraceGIG, Komunikat 544, Katowice, 1972.
7. Kockert, W. Polymere als Injektionsmittel. Plaste und Kautschuk 10:
759-761, 1971.
8. Mitchell, J..K. Innovations in Ground Stabilization. Illinois Section
A.S.C.E. 1972. Chicago Soil Mechanics Lecture.Series, Innovation
in Foundation Construction, March 1, 1972.
9. Technical Date Scheet. Soil Limits-for Grout Injectivity, Halliburton Co.
10, Law tort, H.C. Selective Plugging by Chemical Methods . The Oil Weekly,
Vol. 12, No 12: 46-54,-' 1947 .
'11' R/hanitsin, B .A . Fiziko-khimicheskiye sposoby zakreplenya gruntov
/Physico-Chemical Methods for Soil Hardening/, dsnovaniya Funda-
menty i Mekhanika Gruntov 5:14-16, 1967.
200
-------
12. Korzhenko, L.I., E . I. Malyukov, A.F.Polak. Zakreplenye grunta
mochevino-formaldegidnoy smoloy M-60 v uslovyakh Bashkiria
/Soil Strengthening by Means of M-60 Urea-Formaldehyde Resin
in Bashkirya/. Materialy k VI Vsesoyuznomu Soveshchaniyu po
zakreplenyu i uplotnenyu gruntov, Izdat M .G -U .: 424-428, 1968.
13, Davidov V .V . Ukreplenye gornykh porod smoloy MFS-7 /Soil Stren-
gthening by Means of MFS-7 Resin/. Materialy k VI Vsesoyuznomu
Soveshchanyu po zakreplenyu i uplotnenyu gruntov , Izdat M.G.IT.:
410-411, 1968.
14. Pashkov, D.N., P .G .Kalashnik, V.M.Kozin. Primenenye sintetiche-
skikh Binol v shakhtnom stroitelstve /Application of Synthetic Resins
in Mining Constructions/. Plasticheske massy 8:60-61, 1971.
15. Davidov, V .V . O prinienenyi nekotorykh smol dla zakreplenya gor-
nykh porod /Application of Some Resins to Strengthening of Soils/.
Trudy Vsesoyuznogo Soveshchanya po osvoyenyu mestorozhdeniy
v slozhnykh usloviyakh, Izdat Nedra: 30-39, 1969.
16. Praca zbiorowa. Zwalczanie zagrozen wodnych na przykladzie jednej
z kopaln G6rno£l§skiego Zagtfbia W^glowego /Fighting Against Water
Hazard in a Coal-Mine of the G6rnosl§skie Zaglfbie W^glowe/.
PraceG.I.G, Komunikat No 597, Katowice , 1973.
17. Borodzirlska, E. Zywica mocznikowa 116 /Urea Resin 116/. Komuni-
kat I,C.H.P., No 4/74, Warszawa, 1974.
18, Gresa, J .Pouzitie organickych makromolekulovych hmot pre iniekcne
ciele /Application of Organic Macromolecular Compounds for Grouting
Purposes/. Iniekcne clony v vodnom stavitelstve a vystavba podzem-
nych stien, 1 . Sbornik prispevkov: 263-280, 1968.
19. Technical Date Scheet. Herculox, Halliburton Co.
i
20. Ramos, J,, H .C .McLoughlin. Method of Sealing or Consolidating
Earthen Formation. Pa. USA, 3176471, 1965.
21, Koch, R ,R ., J.Ramos. Method of Consolidating Sands, Earthen For-
mation and the Like . Pat. USA . 3237691, 1966.
22, Ziangirov, R.S., L .V .Goncharova , Umenshenye vodopronikaemosti
peskov karbamidnoy smoloy /Lowering of Water Permeability by Means
Of Carbamide Resin/. Voprosy Inzhenernoy Geologii i Gruntovedenya,
Izdat M.G .U,: 344-350, 1963.
201 ;
-------
23, Voronkevich, S.D., E .N .Ogrodnikova . Issledovanye uprochnenyn
peskov karbamidnymi smolami /Studies on Sand Stabilization by Means
of Carbamide Resins/. Voprosy Inzhenernoy Geologii i Gruntovedenya,
Izdat M.G.U.: 349-359, 1968.
24, Rzhanitsin, B .A ., N .A .Bleskina . Zakreplenye peschatogo grunta
karbamidnoy srnoloy /Strengthening of Sand Soil by Means of Carbami-
de Resin/. Isskustvennoe zakreplenye gruntov, Sbornik 39: 5-10,1960.
25, Tchaykova, E .S . O stoykosti peska zakreplennogo karbamidnoy smoloy
• v agresnivnykh sredakli /Durability of Sand Stabilized by Carbamide
Resin in Aggresive Media/. Osnovanya, fundamenty i pozemnye sooruz-
henya. Sbornik trudov No 39:131-135, 1970.
26. Stepanyan, V .E ., M .A .Astryan, A .A .Agaronyan . Primenenye polin>e-
rov povyshaemykh prochnost i vodopronikaemost gruntov /Applicn tion
of Polymers Raisning Strength and Water Permeability of Soils/. Gitro-
tekhnika i melyoratsia 2:27-35, 1962.
27. Falkiewicz, A., M .Grochowski . Sposob wytwarzania s'rodka przeznn-
czonego do stabilizacji grunt6w /Method of Production of a Soil Sta-
bilizing Agent/. Pat. PRL. 65519, 1972.
28. Lunyov, L ., G.Panteleev. N.Borodin, L.Hartmann, P.Butther, V .Oa-
vidov, N .Brodkina, .S .Suschenkova . Isolier - und Stabilisierungsmittel
fuer Grundungen, Dichtungsschuetzen u.a. inbesbndere Grundflaechen
zur Haufenlaugung von Eizen in alkalischen Medi'en . Pat.GDR, 94151,
1972.
29. Krahl M. Verfahren zur Verfestigung von Boden und zur Abdichtung
poroeser Bauwerke. Pat. GFR . 1050276, 1969.
30. Wirpsza Z., J .Brzezinski. Aminoplasty /Aminoresins/. WNT1, Wnr-
szawa , 1970 .
31, Rabek T. Teoretyczne podstawy syntezy polielektrolitow i wymienia-
czy jono\vych /Theoritical Ground for Synthesis of Polyeletrolytes and
Ion Exchangers/. PWN, Warszawa, 1960.
32. Wirpsza Z, Chemizm kondensacji przemyslowych zywic mocznikowo-
formaldehydowych /Chemism of Condensation of Indvistrial Urea -
1 Formaldehyde Resins/. Przemysi Chemiczny 37: 38-43, 1958.
202
-------
33 t Wirpsza Z. Chemizm kondensacji przemysicnvych zywic mocznikowo-
formaldehydowych/Chemism of Condensation of Industrial Urea-
Formaldehyde Resins/ . Sprawozdanie I .T .S . Nr 71/62. Warszawa,
1962,
34. Depczyriska-Krogulec E., N.Krogulec. Katalog tworzyw sztucznych
/Cataloque of Plastics/, Vol. 1, WKC, Warszawa, 1973.
35. Wirpsza Z . Katalizatory kwasowe do utwardzania aminoplast6w/Ancid
Catalyzers for Hardening of Aminoresins/. Polimery 10: 519-524,
1965.
36. Wirpsza Z. Ditto. Part. Two. Polimery 14:152-156, 1969.
37. Walker.I.F. Formaldehyde, Reinhold Publ. Corp., New York, 19G4.
38. Chuvelev, V.K. O sinereze zhela karbamidnoy smoloy v kapitarno-
porovom prostranstve /Syneresis of Carbamide Resin Gel in Capillary
Medium/. Materialy k VI Vsesoyuznomu vSoveshchenyu po zakreple-
nyu i uplotn,enyu gruntov, Izdat M .G .U .: 404-405 , 1968.
39. Davidov V .V ., N.E.Og'neva. O primenenii melamino-mochevino-for-
maldegidnoy smoly modifitsirovannoy akriloamidom dla ukreplenya
obvodnennykh peskov /Application of Melamine-Urea-Formaldehyde
Resin Modified by Acryloamide to Strengthening of Watered Sands/.
Materialy IV Vsesoyuznogo Soveshchanya po zakreplenyu i uplotnenyu
gruntov, Izdat G .P.I.: 70-72, 1974.
40. Chuprunov G., G. El kin. Zakreplenye peskov rastvorami smol /Stren-
gthening of Sands by Resin Solutions/. Metrostroy 4:21-22, 1968.
41. Kozin V.M., N .1 .Gayvoronskaya, V .1 .Krikunova, S.M. Chumachenko .
Sostav dla zakreplenya gruntov /Medium for Hardening of Soils/. Tat.
USSR. 248549, 1969.
42. Praca zbiorowa. Analiza polimer6w syntetycznych /Analysis of Syn-.
thetic Polymers. Collective Work/. WNT, Warszawa, 1971.
43. Hrynkiewicz R., H . Wielog6rska . Oznaczanie formaldehydu w po-
wietrzu atmosferycznym /Determination of Formaldehyde in the
Atmospheric Air/. Sprawozdanie IMGW, Nr 252.2.04, Warszawa 1974
44. Putilova I. Cwiczenia laboratoryjne z chemii koloid6w /Laboratory
Exercises in Colloid Chemistry/. P,WN, Warszawa 1955.
203
-------
45, F.Bocliever, I .V .Garmonov, A.B.Lebedev, V . M .Shestakov . Osnovy
gidrogeologicheskykh raschetov /Bases of hydrogeological countings/,
Izdat. Nedra, Moskwa, 1969.
46. I.E.Zhernov, V .M .Shestakov . Moclelirovanye filtratii podzemnykh
vod /Modeling of underground water flow/. Izdat. Nedra, Moskwa,
1971,
204
-------
SECTION XV
BIBLIOGRAPHY
Adamovich A .N., W.D .Kollunov . Cementacya osnovaniy gidrosoruzhenij .
/Cement grouting of hydraulic constructions foundations/, Izdat . Energya,
Moskwa 1964.
Cambefort II. Injections des Sols. Eyrolles, Paris, 1964.
Detin V .F . Opytnye raboty v proizvodstvennych uslovyakh po inekcyi nes-
vyazanykh gruntov smolamy na osnove fenolospyrtov y summarnykh
slancevykh fenolov /Research on loose soil injection with phenols
resins carried out in the practical conditions /Izvestya Vsesoyuzmnvo
Nauchno-Issledovatelskovo Instituta Gidrotekhriiki, T.94, 1970.
Detin V .F ., A .N .Adamovich . Laboratornye issledovanya po zakreplenyu
peschatykh gruntov smolamy na osnove fenolospyrtov y summarnykh
slancevykh fe noloy /Laboratory research on sandy grounds grouting
by means of ph.ends resins . /Izvestya Vsesoyuznovo Nauchno-Isslrdo-
vatelskovo Instituta Gidrotekhniki, T.94, 1970.
Erikson H.B . Strenghtening rock by injection of chemical grout. Journal
of the soil Mechanics and Foundations Division ASCF .
Ibragimov M .J . Mekhanizacya rabot po khimicheskomu zakreplenyju
gruntov. /Mechanization of chemical grouting of the soils/ .Materially
soveschanya po zakreplenyu i uplotnenyu gruntov. Tbilisi 1964.
Karol R .H . Chemical grouting technology, Journal of the Soil Mechanics
and Foundations Division A SCE, January 1968.
Karol R .IT. Symposium on grouting: Grouting in flowing water and strnti-
fied deposits .Journal of the Soil Mechanic and Foundations Division
ASCE, April 1961 ,
^
Lupiac L., H.Navarro, F .Ottman, J .Bosse . Acces et intercommunications
de la Station ,"Auber" /Phase V/.Traitement confortatif des sables
de Beauchamp par injection de gols de silice.
205
-------
APPENDIX A
PRINTOUTS OF PROGRAMS
FOR COMPUTATIONS
OF INJECTION
206
-------
]0 SELECT PRINT 005
70 REM INJECTION - PATTERN. Al
10 REM COMPUTING nrr, FLOW TIME OF THE GROUT
40 DIM T(.ioo),R(ioo),q(ioo),A$2,Pi$3
.50 INPUT "GIVE TUE UNIT OF LENCTU",A$
60 INPUT "GIVE TUF UNIT OF TTMF,",B!;!
70 PRINT "GIVE THH FOLLOWING DATA"
RO PPJ.TIT- " II - OVFRPRESSURF, TNTRODUCINO Tjir TROUT"
90 PRINT " R - FXTKRNAL RADT.UP"
1.00 PRINT "RO - RADIUS OF INJECTION UOT.F,"
110 TRINT "KO - COF,wFICir,UT OF T'F.RW.AP.T.LI'T'V FOR TJIP TJOUID"
17.0 PRINT " PRECEDING 'HIE CROUT"
130 PRINT "KE - COEFFICIENT OF PERMEATU.LTTV ^OR THE CROUT"
140 PRINT " E - COEFFICIENT OF THE flOIL PORO'UTV"
150 PRINT "N - OUANTTTY OF COMPUTATION"
IfiO IWUT "l!,R,RO,KO,KE,E,N"fU,R,Rl,K,K.l ,F,N
170 TJ^IMT "HIVE SUCCESSIVELY TUE VALUES OF RADiur;"
IflO FOR T=ITQ N
1^0 PRINTUSINC, 200,1
200 %R(///'//)
210 INPUT R(I)
220 NEXT I
250 A1-R.1
VOR T.m.l'i'o M
NEXT I
3')0 SELECT PRINT 211
310 PRINT "INJECTION - PATTERN Al"
320 ^RINT
330 PRINT "COMMUTING THE FLOW TIME OF THE CROUT"
340 PRINT
350 PRINTUSINC, 410,U,A$
207
-------
360 PRTW'USTNO /!20,R,A.$
370 T'RTIlTUSTNr, A30,n],A$
inn PRTNTHSTNC /I/IO,K,A$,?J$
390 PPTNTUSriO A50.K.1 ,A$,n$
400 PRTNTUS1NO 4GO,E
410 % i! « /'///////'.//// ////
/i7.0 %;• R " ///////'//.//// ///'
A30 % ' RO- /////////'.//// ////
A/,0 % KW= //.///'////! ! I! //////'////
/i50 % KT= //,////////! I M_ «///////
A60 % N - //.////«
470 PRINT
AP,0 PRINT " R T(R) 0/M"
490 PRT.NT11ST.NO 500, A$,R$ , A$ ,B$
500 % [/'f'l [//////] [////?.//////']
310 FOR T=lTrt N
3?.0 •PRTNTUSTNC 540, R (I) ,T(T) ,Q(T.)
JO NIWT I
'540 %/'///'////, //// ////////////////////. //// //. ///////'! ! ! !
550 END
208
-------
1.0 SELECT T>RT.NT 005 . ~"
20 REM INJECTION PATTERN A2
30 KEM COMPUTING THE INJECTION RANGE
40 DIM T(100),R(100),Q(10n),A$2,P,$3
50 INPUT "GIVE THE UNIT OF LENGTH", A$
60 INPUT "GIVE THE TTNIT OF TI.ME",P>$
70 "HINT "GIVE THE FOLLOWING DATA"
80 PRINT " II - OVERPRESSURE INTRODUCING THE GROUT"
90 PRINT " R - EXTERNAL RADIUS"
100 PRINT "RO - RADIUS OF INJECTION UOLE"
.130 PRINT "KO - COEFFICIENT OF r-RRMEAniLITY FOR TUF LTOUTD"
120 PRINT " PRECEDING THE GROUT"
130 I'RINT "KE - COEFFICIENT OF PERMEABILITY FOR THE GROUT"
1AO VRINT " E - COEFFICIENT OF TUE SOIL
1.50 "PINT " ;j - OUANTITY OF COMPUTATIONS"
jr>n TNPUT "u,R,Rn,KO,KK,E,N",n,R,Ri ,T:,KI,F,N
1.70 PRINT 'GIVE SUCCESSIVELY THE TIME VALUES"
1FO FOR T=ITO N
190 I'RINTUSING 200,1
200 7!T(W)
?10 INPUT T(I)
22.0 NEXT I
230 A2=LOG (R) -K*LOG (R.I ) /Kl
250 A.1=R1 !2''--0.5
260 ])=, 00001
27H FOR I=l'ro N
280 R2=(R-Ri)/2
2.90 P=R2.
300 T=I;/ (K*]|) * (p i 2* . 5* (A7>A3* (LOG (P) - . 5) ) -Al )
310 IF AnS((T-T(l))/T(l)) [D THEN 380
IF
^=P
350 GOTO J10
209
-------
360 P-P+R2
370 GOTO 300
380 R(T)=P
390
400
410 SELECT PRINT 211 '
420 PRTHT "INJECTION - PATTERN A2"
/i 30 PRINT
440 PRINT "COMPUTING THE INJECTION RANGE"
A 50 PRINT
460 PRINTUSTNG 57.0,11,A$
470 PRTNTUP.TNO 530,R,A$
400 PRTNTUPTNf! VtO,Rl,A$
A»0 PRITITl'SINH 550,K,A$,n$
500 PRTNTUSINO 560,.K] ,A$,P$
530 PRTNTUSinc 570,E
520 7,' 11 - /'///////'.//// ////
530 % R = /////////'.//// ////
5/.0 % RO- /,'////////,//// ////
550 ?! KW= //,/////'//!!!! /'/////////
560 % KI= //./////'/'111! /'////////'
570 % N - //,////////
5RO PRINT
590 PRINT " T R(T) _ Q/?t"
600 PRTNTUHTNG 610,0$ ,A$ ,A$,11$
6.10 % [//////] [////] ' [////2////'/'
620 FOR I«1TO N
630 PRItmTST.Nr, 650,T(T),R(I),0(I)
6AO NEXT I
650 %//////////////////////, //// ////////////, ///////' //, //W M
660 END
210
-------
1 0 SELECT PRINT 005
20 REM INJECTION - PATTERN Bl (BULB)
30 DIM K(.100),T(]00),R(100),Q(]00),A$2,B$3
40 IN^UT "GIVE THE UNIT OF LENGTH", A$
50 INPUT "GIVE THE WIT OF TIME",B$
60 PRINT "GIVE THE FOLLOWING DATA"
70 PRINT " H - OVERPRESSURE INTRODUCING THE GROUT"
,10 PRINT " R - EXTERNAL RADIUS"
90 PRINT "RO - RADIUS OF INJECTION HOLE"
100 PRINT "KO - COEFFICIENT OF PERMEABILITY FOR TUE LIQUID"
110 PRINT " PRECEDING TJ-1F GROUT"
120 PRINT " E - COEFFICIENT OF THE SOIL POROSIT^"
.1 30 PRINT " M - QUANTITY OF COMPUTATIONS"
l/iO INPUT lH,R,RO,KO,E,N",H,R,Rl,^fE,N
150 PRINT "GIVE THE TIME STEP AND COEFFICIENT OF PERMEABILITY"
160 PRINT "FOR THE GROUT"
170 FOR I=1TO N
1P.O PRINTUST.NG .190,1,1
190 %T(W), K(W)
200 INPUT T(I),K(I)
210 NEXT I
220 02=2*H*K/LOG(R/R1)
230 V2-0
240 FOR I=1TO N
250 01=02
260 03=^2
270 o«,5*(Ql-f-Q2)
280 V=Q*T(T.)
290 V1=V2+V
300 R2«SQROn./T?+R] !2)
310 02=2*n/(LOG(R2/R.1)/K(l)+T,OC(P/R2)/K)
320 IF ABS((Q3-Q2)/02)].001TUEN 260
330 V2-V2+V
350 Q(I)-.5*(01-W)2)
211
-------
3dO NEXT I
370 SELECT PRINT 21.1
3HO PRINT :PR TNT
390 PRINT "INJECTION - PAT1EKN JU (BfTLB)"
4 00 T'RT.NT : PR INT
4.10 PRINT1ISTNG Af.O,n,A$
A20 PRTNTUPJINC A70,R,A$
A30 Pn.IN'niSINC ARO.R] ,$
ViO PRTNTUPING A90,K,A$,B$
450 PRINTUSTMH 500,E
AfiO % It "VMMJHHI /'/'
470 % R •=//////////.////// ////
ARO % R0=/////////'.////// /'/'
490 % KW=//.//////l !! I ///////////
500 % N -//,//////
510 PRINT :PRINT
520 PRINT " T RH 0/ff
530 PRINTIIRINf, 5AO,B$ ,A$ ,A$ ,R$ ,A$,B$
5AO 7, [/'////] [////] [////2////'//] (/'//////'/']
550 T=6
5r,o. FOR i-i'rn N
570 T=T4-T(I)
580 PRTNTUSINr, fiOO,T,R(l) ,Q(I)*//PT,K(l)
5(>0 NEXT I
MO %////////////. //////// ////, //////// //, ////////! ! I I /'.
610 END
212
-------
.10 SELECT PRINT 005
20 T?T;M INJECTION - PATTERN P.2
30 REM P,UJJ3 DILATED
40 DIM K(]00),T(100),ROOO),R2(100),Q(100)>A$2,P$3
50 SELECT PRINT 005
60 INPUT "GIVE THE UNIT OF LENGTH",A$
70 INPUT "GIVE THE UNIT OF TIME",B$
80 PRINT "GIVE THE FOLLOWING DATA "
90 PRINT " 11 - OVERPRESSURE INTRODUCING THE GROUT"
100 PRINT " R - EXTERNAL RADIUS"
110 PRINT "RO - RADIUS OF INJECTION HOLE"
120 PRINT "KO - COEFFICIENT OF PERMEABILITY FOR THE LIOUT.D"
130 PRINT " PRECEDING THE GROUT"
17(0 T-pjNT "Kl - COEFFICIENT OF r^RMEARILTTY FnR Tnr;"
150 PRINT " DILATING LIQUID"
KiO PRINT "F- COEFFICIENT DF THF SOIL POROSITY"
170 PRINT " N - OUANTITY OF TIME SETT'S"
.180 PRINT "Ml - NUMBER OF S'T.p INITIATING THE DILATATION"
190 INPUT MH,R,RO>KO,1'l,E,N,N1",n,R,Rl,lVn.,E,N,N.l
200 TRINT "GIVE THE TIME STEPS AND COEFFICIENTS OF"
210 PRINT "PERMEABILITY FOR THE GROUT"
220 FOR I=1TO N
2.TO TFT.NTUSINO 2AO,T.,I
2AO %T(/////'),K(/'<]l*K/LOG(R/R;i)
280 V?=0
290 v.l=>0
300 R3«P1
310 "OR I^ITO N
320 01=n2
330 man.1?
340 0=.5*(0..!-K)2)
350
213
-------
360 Vl="2-i-V
3 70 R2«pnR(Vl/T->R112)
380 IF T [NITUF.N 4]0
T90 vi=V3+V
400 R3=SnR(Vl/E-HU!2) '
420 IF Ann((03-Q2)/Q2)],001TlIRN 330
430 V2=V2+V
4 40 IF T[N.1TIIF,N 460
450 V3«V.3+V
*
460 R2(I)-R3 '
4 70 R(I)=R2 •
4 00 0(T) = ,5*(01>Q2)
490 NF.XT I
500 SFTJ'CT T'P.INT 211(150)
510 PRINT :PRINT
57.0 PRINT "INJECTION - WVTTRRN B2"
530 PRINT "BULB ni.J-ATFJ)"
540 PRINT SPRINT ,
550 PRIN'nTSTNn 610,II,A$
570 PRTNTUFW, 630,R.I,A$
580 PRTNTliniMn 640,K,A$,B$
590 PRTNT.UPTNr, 650,K.1 ,A$,B$
600 PRINTUT'TNO 660, F,
610 %1I - //W.////// ////
630 %RO - it 11 it. it Wfl H
640 %KW « /'./////'/'!!!•! //////'////
650 %K1 « //,////////!! ! ! W/M
660, %tl H //,/'///'//
670 PRINT :PRINT
fiMO PRINT " T RB 1W n/f
KT"
6 90 PRTNT1IS1NO 700,B$,A!?,A$,A$,R$fA$."$
700 % [//////] [ini] [-"/'I r*/n/y.y»yn r^'/«/
214
-------
7 10 T«=0
720 FOR T=1TO N
730 T»T+T(T)
740 PRTMTUSTNO 760,T,R(I) ,R
750 NEXT I
760 %/////>//////,//W /////'/'.//////// ////////./'////// //.///////'!
I !
7 70 END
215
-------
TO SKT.FCT "HINT 005
2n RF,H TtuF.m'ioM - "ATTORN m (?m,?,)
30 DIM K.(100),T(100),R(100),Q(100),A$2,R-03
40 INPUT "HIVE TTin UNIT OF
50 TMJ'UT "OIVI! THF, UNIT OF
do rnTiiT "OTVF, TI?K FOLLOWINC
70 PRINT " I! - OVF,RPRF,FPTtnr, T.NTRODUniW TJIF
,TO PRINT " ", - EXTF.PNAT, PAniT^"
90 PRINT "RO - P.Aninr- OF T.MJFn'ION nnT,F"
1.00 PRINT "KO - rnF.FFICTFNT OF PF^MFA^.TT,TTY FOP, Tt'F TJOT'in"
310 1in,T.NT " riRT^FDTNr TTIK nROUT11
17.0 PRINT " K - COF^FTflTfTt'r OF TUP POT.T,
130 T'RTJ.JT " T - TT"P STfiP"
.1/iO "PINT " TJ - nUANTTTV nv TTMK S
150 T.rjT'UT "H,P,RO,KO,F,,T,N",H,R,R1 ,
i r,n PRINT "nivF, TUF COEFFIHIKNTS OF
170 PRINT "FOR Tjtr, OROITT"
1MO FOR T=1TO N
190 PPITITURT.NG ?.00, 1
200 %!<(//////)
2.10 INPUT "K(T.)",K(I)
220 NKXT I
230 R(1)=R1
2AO 02=2*l!*K/T,or;(R/Rl)
250 "flu T-=1TO N
2dO ni«02
270 03«n2
7.90 n(T.)=0
300 A.1.=0
3.10 FOR J=].TO I
320 R(jH-1)=SOR(n(l-,T-n)*T/F-fR(J) 17)
330 Al.«A1^I,or, (R (J-M) /w (,T) ) /K (J)
3/i 0 NFXT J
350 n?.»2*n/(M+l,nr;(T?/R(T+l))/'0
216
-------
360 IF AHS((03-02)/02)],OOr.r)iEN 270
370
3RO
390 NEXT I
400 SELECT PRINT 211
410 PRT11T :T'RTNT
420 PRINT "r.NJECTTON - PATTERN 01 (BULB)"
430 PRINT :"RT.NT
440 PRINTIJSINO 500,U,A$
450 PRTNTUST.Nr, 5.10, R,A$
460 FRINTUniNn 520,R1,A$
470 "RTNTUfUTir, 530,K,A$,B$
480 PRinTTIPINO 540, E
490 PRTNTUSIIir; 550,T,H$
500 % I! - ///////'.////// /'//
510 % R - ////////.////// ////
520 % RO « ////////.////// ///* •
530 % KW - //.///////'I!!! //////'////
540 % N « //.///'/'/'
550 % T - //////W,////// //////
560 PRINT' :PRINT
570 PRINT " T RP. , 0/n ?a(t
5HO PRINTUSIlir; 590,B$,A$,A$,B$,A$,B,$
590 % [/'/'//]
600 FOR I«n'0 N
6.ta PRINTUSTMH 630,1''(T,T(T) ,0(1)
620 NEXT I
630 %///'///////'.///'//// ////,/'////// //.///'/'/'111! /'./'/""MM!
640 EN!)
217
-------
10 SELECT PRINT 005
20 REM INJECTION - PATTERN C2
30 RF,M ]?ULn DILATED
40 DIM r(100) ,T(100) ,R(100) ,R2 (.1 00) ,0(1 00) ,A$2,P$3
50 SELECT PRINT 005
fio INPUT "GIVE THE UNIT OF LENGTH",A$
70 INPUT "GIVE THE UNIT OF TIMK",B$
80 PRINT "GIVE TUE FOI,LOWINn DATA"
90 PRINT " 11 - OVER^RF.SSURF INTRODUCING THE HROUT"
.100 1'RINT " R - FXTERMAL RAni.lTR"
110 T^INT "PO - RADIUS OF IRTKHTION I'OLF,"
1.20 PRINT "KO - CO^FFiniKNT OF PF,T1MFA^IT,ITV FOR T^F,
1.30 ppj.nT " pRrnrjiiro THE IROUT"
IAO PPIMT "KI - COF.FFICIF.TIT OF T-FPMFAPTTJTV FOP,"
150 PRINT " TUF, DILATING LTOUID"
1 60 PRINT " I5! - roi'^FICIKNT OF TUF SOU, POROSITV"
170 PRINT " N - OUANTTTV nv TJMF RTEPS"
''HO PPTMT " T - TT.TTT' SfFP"
190 VPT.NT "Mi - N'lN^T7" OF r^'^P TNTTIAf''TNn TUF DIT,/\TATinN"
200 INPUT "ll,R,RO,T'',0,Tn , F,N,T,N1M,U,R,R1 ,K,F1 ,F,N,T,N1
2.10 PRINT "GIVF, THE COEFFI.niFNTS OF
220 "RINT "FOR THE OROUT"
230 I'OR T. = ].TO N
2AO VPvINTITSING 250,1
250 %K(W)
260 INPUT K(I)
270 NFXT I
2RO R(!)=R1.
290 n?.= 2'M"M«
350 o(T)=o
218
-------
360 Al»0
370 IF T. [N1TI1EN A30
380 FOR J=1TO I-N1-K1
390 R(J+l)=RQR(q(I-J+l)*T/E+R'/>//,//////# ##
690 %N - ft. ////////
700 %KW - //.////////!!!! «///////
219
-------
710 %K1 = //.////////III! ///////////
720 PRINT : PRINT
730 PRINT " T Rtt RW ' p/Tl
KI"
740 PRINTUSINO 750, B$ ,A$,A$,A$,fl$,A$,R$
750 %
760 FOR I«1TO N
770 PRTTITURINO 790,T*I ,R2(I) ,T(I) ,9
780 NEXT I
790 %//////////// , //////// //////// , //////// ////////.//////// tt.Mif ! ! I ! /' . ///'/V ! I
I !
000 END
220
-------
APPENDIX B
PHOTOS OF THE BLOCKS OBTAINED
ON THE LABORATORY AND FIELD
INVESTIGATIONS OF GROUTING
221
-------
1
B-l. Test 1-bulb
B-2. Test 2 bulb
222
-------
B-3. Test 3-bulb
B-4. Test 4-bulb
223
-------
B-5. Test 5-bulb
B-6. Test 6-bulb
224
-------
B-7. Test 7-bulb
B-8, Test 8-bulb
225
-------
B-9. Test 9-bulb
B-10. Test 10-ring
226
-------
B-ll. Test 11-ring
12
B-12. Test 12-ring
227
-------
13
B-13. Test 13-ring
14
B-14. Test 14-ring
228
-------
15
B-15. Test 15-ring
R-16. Test, 16-ring
229
-------
B-17. Test 17-ring
18
R-18. Test 18-ring
230
-------
B-19. Test 19-ring
B-20. Test 20-ring
231
-------
B-21. Test 21-ring
22
B-22. Test 22-horizontal plate
232
-------
B-23. Test 23 - horizontal plate
B-24. Test 24 - horizontal plate
233
-------
25
B-25. Test 25 - horizontal plate
26
B-26. Test 26 - horizontal plate
234
-------
27
B-27. Test 27- horizontal plate
28
B- 28. Test 28 - horizontal plate
235
-------
29
B-29. Test 29 - horizontal plate
B-30. Tests Tl, T2, T3 - bulbs
236
-------
T4
B-31 . Test T4 - bulb
T5
B-32. Test T5 - ring
237
-------
T15
B-33. Test T15 - ri
ring
B-34. Tests T6 -T14 - vertical curtain
238
-------
T10T16
B-35. Tests T10, T15, T16 - vertical curtain
239
------- |