ENGINEERING PROPERTIES OF THE
ORINOCO CLAY
by
Robert William Day
B.S.E., Villanova University (1976)
M.C.E., Villanova University (1978)
SUBMITTED IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE
DEGREES OF
MASTER OF SCIENCE IN
CIVIL ENGINEERING
and
CIVIL ENGINEER
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
December 1980
Robert William Day 1980
The author hereby grants to M.I.T. permission to reproduce and
to distribute copies of this t-esis document in whole or in part.
Signature of Author
/ Department of
'
ivil Engineering
ecember 15, 1980
Certified by
I CZ'les 9'%dd
Thps Su9
sor
Accepted by
Allin Cornell
//'KC.
Cha rman, Department Committee
ARCHIVES
MASSACHUSETTS INSTITUTE
OF TECHNOLOGY
APR 1
1981
LIBRARIES
2
ENGINEERING PROPERTIES OF THE
ORINOCO CLAY
by
Robert William Day
Submitted to the Department of Civil Engineering on December
15, 1980 in partial fulfillment of the requirements for the
Degrees of Master of Science in Civil Engineering and Civil
Engineer.
ABSTRACT
Sediments from the Orinoco River have formed a thick
(30-40 m) deposit of soft, highly plastic clay along vast
areas of offshore Eastern Venezuela. Whereas conventional
practice for the design of oil platforms relies on empirical
use of results from simple strength index testing, this
thesis utilized the SHANSEP method to develop a more reliable
estimation of the in situ undrained shear strength (s )and
deformation characteristics of the Orinoco Clay deposit.
Radiography of sampling tubes containing Orinoco Clay detected
the presence of gas pockets, cracks, and zones of disturbed
clay and also served to identify the best quality specimens
for sophisticated laboratory tests such as oedometer and K0
Consolidated-Undrained Direct Simple Shear (CK0UDSS) tests.
Results of oedometer tests run on undisturbed tube
samples from two borings separated by 125 km indicate that
the Orinoco Clay deposit at both borings has essentially the
same maximum past pressure and is either normally consolidated
or slightly overconsolidated. The oedometer and CK0UDSS test
data reveal that the Orinoco Clay exhibits normalized behavior,
but with two strata having significantly different engineering
properties. The lower stratum is more compressible with a
normalized undrained shear strength less then the upper stratum.
This distinct difference in engineering properties is probably
caused by a considerable increase in the content of swelling
minerals in the lower stratum.
The SHANSEP undrained shear strength profiles at the two
widely separated borings were almost identical, whereas su
from the strength index tests (e.g. UU Triaxial, Lab Vane, etc.)
yielded wide scatter due to sample disturbance, strain rate
differences, and anisotropy effects. Because of the very
similar engineering properties and SHANSEP s profiles, and
corroborated by geophysical data, it is concluded that the
3
Orinoco Clay exists as basically the same deposit around
and between the two borings.
Thesis Supervisor:
Title
Charles C. Ladd
Professor of Civil Engineering
4
ACKNOWLEDGMENTS
I am indebted to my parents for their encouragement
in completing this thesis.
I would like to especially thank Professor Charles C.
Ladd, my thesis supervisor, for his constructive criticism
and Instituto Tecnologico Venezolano del Petroleo
(INTEVEP)
for their financial aid.
My thanks also to Enrique Urdaneta Lafee and Aziz M.
Malek for their friendship and assistance in the laboratory.
5
TABLE OF CONTENTS
PAGE NO.
TITLE PAGE
1
ABSTRACT
2
ACKNOWLEDGMENTS
4
TABLE OF CONTENTS
5
LIST OF TABLES
7
LIST OF FIGURES
8
LIST OF SYMBOLS
10
CHAPTER 1.
13
INTRODUCTION
1-1 ORINOCO CLAY
13
1-2 BORINGS El AND Fl
14
1-3 ORGANIZATION OF THESIS
17
CHAPTER 2.
SHANSEP METHOD
22
2-1 TV, LV, AND UUC TESTS
22
2-2 SHANSEP METHOD
24
2-3 SUMMARY
27
CHAPTER 3.
INDEX PROPERTIES AND COMPOSITION OF
ORINOCO CLAY
30
3-1 UNDRAINED SHEAR STRENGTH FROM STRENGTH INDEX
TESTS: TV, LV, AND UUC
3-2 INDEX PROPERTIES:
NATURAL WATER CONTENT
32
3-3 INDEX PROPERTIES:
ATTERBERG LIMITS
32
3-4
IN SITU VERTICAL EFFECTIVE STRESS
3-5 COMPOSITION ANALYSES:
3-6
MINERALOGY
SALT CONCENTRATION AND ORGANIC MATTER
3-7 SUMMARY
33
34
35
36
6
PAGE NO.
CHAPTER 4.
RADIOGRAPHY
4-1 INTRODUCTION:
45
X-RAYS
45
4-2 DESCRIPTION OF M.I.T.'s RADIOGRAPH FACILITY
46
4-3 RADIOGRAPHY OF SAMPLING TUBES CONTAINING
ORINOCO CLAY
48
4-4 SUMMARY
52
CHAPTER 5.
5-1
STRESS HISTORY AND CONSOLIDATION PROPERTIES
INTRODUCTION:
TESTS
TEST PROCEDURES FOR OEDOMETER
60
60
5-2 EFFECTS OF SAMPLE DISTURBANCE
62
5-3 STRESS HISTORY
65
5-4 COMPRESSIBILITY AND COEFFICIENT OF
CONSOLIDATION
66
5-5 EMPIRICAL CORRELATIONS
68
5-6
68
SUMMARY
CHAPTER 6.
NORMALIZED SOIL PROPERTIES AND SHANSEP
STRENGTH PROFILES
77
6-1 NSP FROM NORMALLY CONSOLIDATED CK UDSS
TESTS
77
6-2 OVERCONSOLIDATED CK0UDSS TEST DATA
82
6-3 ANISOTROPY
83
6-4 SHANSEP STRENGTH PROFILES
85
CHAPTER 7.
SUMMARY AND CONCLUSIONS
REFERENCES
101
107
APPENDIX A.
CONSOLIDATION TESTS
109
APPENDIX B.
CK0UDSS TESTS
122
APPENDIX C.
CK UC AND CK UE TESTS
138
7
LIST OF TABLES
TABLE
TITLE
PAGE NO.
1-1
SAMPLE LOCATION, TYPE AND PRINCIPAL TESTS:
BORING El
19
1-2
SAMPLE LOCATION, TYPE AND PRINCIPAL TESTS:
BORING Fl
20
2-1
SHANSEP APPROACH
28
3-1.
UNIT WEIGHTS AND EFFECTIVE STRESS
37
3-2
CLAY MINERALOGY SUMMARY FOR BORING Fl
38
3-3
CLAY MINERALOGY SUMMARY FOR BORING El
39
5-1
SUMMARY OF OEDOMETER TEST DATA:
BORING El
69
5-2
SUMMARY OF OEDOMETER TEST DATA:
BORING Fl
70
6-1
SUMMARY OF CK UDSS TEST DATA:
CLAY
N.C. ORINOCO
90
6-2
SUMMARY OF CK UDSS TEST DATA:
CLAY
O.C. ORINOCO
6-3
SUMMARY OF CK U TRIAXIAL TESTS:
CLAY
7-1
ENGINEERING PROPERTIES OF THE ORINOCO CLAY
N.C. ORINOCO
91
92
106
8
LIST OF FIGURES
.TIE
FIGURE
PAGE NO.
1-1
BORING LOCATIONS
21
2-1
APPLICATION OF SHANSEP TO UNDRAINED STABILITY
ANALYSIS USING CK U DIRECT SIMPLE SHEAR TESTS
29
3-1
NATURAL WATER CONTENT AND STRENGTH INDEX
TESTS: BORING El
40
3-2
NATURAL WATER CONTENT AND STRENGTH INDEX
TESTS: BORING Fl
41
3-3
EFFECTS OF DISTURBANCE AND STRAIN RATE ON
SAMPLE F1557
TORVANE DATA:
42
4
3-4
PLASTICITY CHART: ORINOCO CLAY
43
3-5
SALT CONCENTRATION AND ORGANIC MATTER:
ORINOCO CLAY
44
4-1
RADIOGRAPHY OF A SAMPLING TUBE CONTAINING
ORINOCO CLAY
54
4-2
OEDOMETER AND STRENGTH DATA ON SAMPLE
FlS57 FOR COMPARISON WITH RADIOGRAPH
55
4-3
SAMPLE F1557: RADIOGRAPH PRINT SHOWING
SAMPLE DISTURBANCE
56
4-4
SAMPLE E1512: RADIOGRAPH PRINT SHOWING
GAS POCKETS
57
4-5
SAMPLE ElS21: RADIOGRAPH PRINT SHOWING
HORIZONTAL CRACKS
58
5-1
EFFECTS OF DISTURBANCE ON OEDOMETER TEST
DATA: SAMPLE F1557
71
5-2
OEDOMETER TEST DISTURBANCE INDICES:
ORINOCO CLAY
72
5-3
STRESS HISTORY: ORINOCO CLAY
73
5-4
COMPRESSIBILITY AND COEFFICIENT OF
CONSOLIDATION: ORINOCO CLAY
74
9
FIGURE
-TIE
PAGE NO.
5-5
EMPIRICAL CORRELATIONS WITH NATURAL WATER
CONTENT: ORINOCO CLAY
75
5-6
EMPIRICAL CORRELATIONS WITH LIQUID LIMIT:
ORINOCO CLAY
76
6-1
CK UDSS TEST DISTURBANCE INDICES: ORINOCO
CIAY
93
6-2
NORMALIZED STRESS PATHS FROM CK 0UDSS TESTS:
N.C. ORINOCO CLAY
6-3
NORMALIZED STRESS VERSUS STRAIN FROM CK0UDSS
TESTS: N.C. ORINOCO CLAY
95
6-4
NORMALIZED UNDRAINEDCMODULUS FOR CK0UDSS
TESTS: N.C. ORINOCO CLAY0
96
6-5
s lavc VERSUS PI FOR NORMALLY CONSOLIDATED
CL AND CH CLAYS
97
6-6
EFFECT OF OCR ON s /avc
98
6-7
COMPARISON OF UNDRAINED STRENGTH DATA:
BORING El
99
6-8
COMPARISON OF UNDRAINED STRENGTH DATA:
BORING Fl
100
10
LIST OF SYMBOLS
Prefix A indicates a change
A bar over a property indicates value in terms of effective
stress
GENERAL
BBC
Boston Blue Clay
EABPL
East Atchafalaya Basin Protection Levee
z
Depth below mudline
INDEX PROPERTIES
e
Void ratio
e
Initial
Gs
Specific gravity of solids
LI
Liquidity index
P.I.
Plasticity index which equals w1
S
Degree of saturation
w
Liquid limit
w
n
Natural water content
w
Plastic limit
p
Yb
Ysw
Yt
Yw
void ratio
-
w
Buoyant unit weight
Unit weight of salt water
Total unit weight
Unit weight of water
CONSOLIDATION PARAMETERS
cv
Coefficient of consolidation for vertical flow
11
C
Virgin compression index = -Ae/Aloga
Cs
Swelling index
Ca
Rate of secondary compression = Ae /Alog t
CR
Virgin compression ratio = Av/Aloga
vo,
K0ho
the in situ lateral stress ratio for
one-dimensional vertical strain
during deposition
OCR
Overconsolidation ratio = a
RR
Recompression Ratio
SR
Swelling ratio
t
Time
t
Consolidation time for preshear a vc
E:
Vertical strain
avc
Vertical consolidation stress
av
In situ vertical effective stress
av
Maximum past pressure
or a
/lvc
STRENGTH AND DEFORMATION PARAMETERS
E
E
Young's modulus
Undrained secant E
u
E5 0
Eu half way to failure
s uUndrained
s /W
Svc
shear strength
Normalized undrained shear strength where a
is
the consolidation vertical effective stress prior
to undrained shearing (applicable for CKQU strength
tests)
Angle of rotation of the principal stress during
shearing for a CK0U strength test
Shear strain
12
y
Shear strain needed to reach s
Vertical effective stress during shearing
(Direct Simple Shear test)
Th
Shear stress on horizontal plane during shearing
(Direct Simple Shear test)
Slope of Mohr-Coulomb failure envelope
CONSOLIDATION AND STRENGTH TESTS
CK0 U
K0 Consolidated Undrained shear test
CK UC
CK U Triaxial Compression test
CK0 UDSS
CK U Direct Simple Shear test
CK UE
CK U Triaxial Extension test
LV
Lab Vane
Oed
Oedometer test
TV
Torvane test
UUC
Unconsolidated Undrained Triaxial Compression
test
13
1. INTRODUCTION
Laboratory soil tests were performed to determine
the engineering properties of the offshore Orinoco Clay
deposit and the objective of this thesis is to present the
results of those tests.
The SHANSEP method is utilized to
obtain normalized soil properties and the undrained shear
strength profiles at two widely separated borings off the
coast of Eastern Venezuela.
The-engineering properties
of the Orinoco Clay are needed for the design of oil platforms.
1-1
ORINOCO CLAY
Transgression is defined as a rise in sea level relative to the land which causes areas to be submerged and
new deposition to begin in that region.
In the past
fifteen thousand years, sea level has risen about 100
meters caused by the termination of an ice age and melting
of glaciers.
In Venezuela, transgression produced a wider
continental shelf upon which the Orinoco Clay has been
deposited.
The Orinoco River (see Fig. 1-1) has a length of 2500
kilometers and transports an estimated sediment load of
108 tons/year (Butenko and Hedberg, 1980).
The river
deposits most of it's granular soil inland, while the
suspended clay particles are carried into the Atlantic
14
Ocean.
Salt water causes these particles to flocculate
and then the flocs settle to the sea floor.
For the past
fifteen thousand years, clay deposition has produced a
vast and thick "mud wedge", extending up to 60 to 100
kilometers from the shoreline for a distance of about 450
kilometers along the continental shelf, with a maximum
thickness of 50 to 70 meters.
The swift longshore Guyana
Current also transports some of the suspended flocs towards
the West where deposition occurs in the placid waters of
the semienclosed Gulf of Paria (Fig. 1-1).
This offshore
clay deposit composed of sediments derived from the Orinoco
River has been termed the Orinoco Clay
1-2
BORINGS El AND Fl
Jackup exploration and oil production platforms will
be constructed in the Atlantic Ocean within the Orinoco
River delta and in the Gulf of Paria.
The Orinoco Clay
deposit will totally support the jackup platforms and to
determine their stability to ocean waves, winds, and platform dead and live loads, the undrained stress-strainstrength and consolidation properties of the deposit must
be determined.
For the oil production platforms, tubular
steel piles will be driven through the Orinoco Clay deposit
and into the stronger underlying dense sand and stiff clay
strata.
The oil production platforms will not rely upon
15
the Orinoco Clay to support axial loads, but the clay
deposit must resist lateral pile deformations due to
horizontal loads from wind and waves acting upon the oil
In order to determine the resistance of the
platforms.
Orinoco Clay to lateral pile deformations, the undrained
shear strength (su) and the stress-strain characteristics
(e.g. Young's moduli, Eu ) of the clay deposit must be
ascertained.
Borings El and Fl (Fig. 1-1) were drilled to
obtain Orinoco Clay for laboratory soil tests.
The water
depth and thickness of the Orinoco Clay deposit at each
boring are presented below:
-Boring
Water Depth (f t)
Deposit Thickness
El
86
149
Fl
78
134
(ft)
Orinoco Clay was sampled using cylindrical thinwalled stainless steel tubes.
The sampling tubes were
two to three feet long and 0.1 inch thick with an outside
diameter of 3 inches.
Two processes were utilized to
penetrate the sampling tubes into the clay.
At the top
40 to 60 feet of the deposit, the tubes were hammered into
the soil.
At greater depths, Orinoco Clay was obtained
by using Fugro's
"WIP"
sampling equipment which consists
of pushing the sampling tube into the soil at a constant
velocity of about 0.8 inch per second (Fugro, 1979).
After the tube samples were hoisted onboard the Fugro
16
drilling ship, some of the clay was used to classify the
soil and to estimate the undrained shear strength by
*
performing Lab Vane (LV), Torvane (TV),
and Unconsolidated
Undrained Triaxial Compression (UUC) tests.
The remaining
Orinoco Clay was sealed by pouring molten wax into both
ends of the sampling tube.
M.I.T. received 17 tubes
containing Orinoco Clay for laboratory soil tests: 6 tubes
from boring El and 11 from boring Fl.
Tables 1-1 and 1-2
present the sampling tube location and type of laboratory
tests performed on Orinoco Clay specimens for borings El
and Fl respectively.
Each table presents the following
data:
(Column 1) Depth below the mudline of the tube sample.
(Column 2) Sampling tube number; for example, E1512
means sampling tube number 12 from boring El.
(Column 3) Type of sampler used; either "WIP" or
hammered sampler where N is the number of blows (from a
198 pound hammer falling five feet) required to drive
the sampling tube one foot.
(Column 4) The in situ vertical effective stress at
the depth of the sampling tube.
(Column 5) The condition of the Orinoco Clay observed
*
Shannon and Wilson, Inc. Seattle, Washington, manufacture
the Torvane device, a hand operated torsional vane shear
device.
17
upon extrusion from it's sampling tube.
For example,
the Orinoco Clay from tube ElSl2 was highly disturbed
and neither composition nor engineering tests
were perforned.
"Salt"
(Columns 6, 7, and 8) Composition results.
means that the salt concentration of the pore fluid was
determined, "Org" refers to an estimation of the organic
content of the soil, and "Mineral" pertains to X-ray
diffraction analyses to determine the type of minerals
present.
(Columns 9, 10, and 11) Engineering tests.
oedometer
(Oed) and Direct Simple Shear
Mostly
(CK UDSS) tests
were performed upon Orinoco Clay specimens.
Of the 17 tubes containing Orinoco Clay received by
M.I.T.,
four of the tubes had soil suffering from excessive
sample disturbance causing the clay to be too soft to trim
for engineering tests.
1-3
ORGANIZATION OF THESIS
Chapter 1 has introduced the Orinoco Clay and borings
El and Fl.
Chapter 2 discusses Lab Vane, Torvane, and UUC tests
which generally give unreliable values of the undrained
shear strength with large scatter because of sample
disturbance, strain rate effects, and anisotropy.
The
SHANSEP method is presented, which is generally a more
reliable method to determine a s
profile.
18
Chapter 3 presents index properties and composition
analyses of the Orinoco Clay.
Chapter 4 discusses radiography, an invaluable tool
used to detect those portions of Orinoco Clay within the
sampling tubes least likely to be disturbed and hence most
suitable for sophisticated laboratory tests such as
oedometer and Direct Simple Shear tests.
Chapter 5 presents the stress history and consolidation
properties obtained from oedometer tests.
Chapter 6 presents the normalized soil properties
obtained from Direct Simple Shear (CK0 UDSS), K
Consolidated
Undrained Triaxial Compression (CK UC) and Extension (CK UE)
tests and the SHANSEP undrained shear strength profiles at
borings El and Fl.
Chapter 7 is the thesis conclusion.
TABLE 1 -1
Depth
No.
SAMPLE LOCATION, TYPE AND PRINCIPAL TESTS:
Salt
(kg/cm )
(ft)
Engineering(2)
Composition
(1)emarks
Type
BORING El
Org.
Mineral.
Oed.
CKoU
-
-
-
-
-
Uniform clay with
gas pockets
yes
yes
yes
Oed-l
DSS-2
DSS-3
form clay with
yes
yes
yes
Oed-2
-
yes
yes
yes
Oed-3
DSS-
37-40
12
N-3
0.77
Highly disturbed
55-57
15
N-10
1.13
83-84
18
WIP
1.74
98-100
21
WIP
2.08
Other
-
Effect of
salt on wL
H
-
DSS-4
horiontalcrac
-
TC-3
113-116
24
WIP
2.41
Disturbed
133-136
27
WIP
2.84
Uniform
(1) Computed for Ga - 2.72 and
(2) Test No:
S - 100%
clay
yes
yes
-
yes
yes
yes
-
Oed-13
Oed-14
(see Table 3-1)
DSS - Direct Simple Shear; TC - Triaxial Compression; TE - Triaxial Extension
-
DSS-13-
-
k0
TABLE 1-2
Depth
no.
Type.
-
ov
SAMPLE LOCATION, TYPE AND PRINCIPAL TESTS: BORING F1
(1)
Remarks
Salt
(kgycm2)
(ft)
Composition
Mineral.
Org.
(Engineering)(2)
Other
CK U
Oed.
yes
yes
-
-
yes
yes
yes
Oed-5
DSS-12
Uniform clay
yes
yes
-
Oed-9
DSS-6
0.93
Slightly disturbed with
few horizontal cracks
yes
yes
yes
WIP
1.20
Disturbed
yes
yes
yes
-
18
WIP
1.22
yes
yes
yes
Oed-4
DSS-l1
-
81-83
21
WIP
1.51
yes
yes
-
Oed-8
DSS-10
-
96-98
24
WIP
1.80
yes
yes
yes
Oed-6
DSS--
111-113
27
WIP
2.09
yes
yes
yes
Oed-1-
126-128
30
WIP
2.38
127-130
57
WIP
2.41
25-27
54
WIP
0.44
27-29
9
N=4
0.48
36-38
12
N-8
0.64
51-52.5
15
WIP
65-67
55
66-68
Disturbed
horizont
a
i
few
Uniform clay
Platy Structure
Platy Structure,Disturbed
Uniform clay
.
.
-
yes
yes
yes
Oed-12
Oed-18
II
(1) Computed for Ga = 2.72 and S = 100% (see Table 3-1)
(2) Test No;
-
Oed-16
Very uniform clay
-
Oed-11
Oed-7
Uniform clay with
shell fragments
-
-
DSS = Direct Simple Shear; TC = Triaxial -Compression; TE - Triaxial Extension
-
S_
E-i
t~J
0
SCALE I a 2,000,000
N
I
TRINIDAD
GULF OF PARIA
BORING El
-.
..
H
:
VENEZUELA
RINOCO RIVER.-
FIGURE 1-1
BORING LOCATIONS
. ..
BORING Fl
-- '1
.....
22
2.
2-1
SHANSEP METHOD
TV, LV, AND UUC TESTS
Several types of engineering tests can be used to determine the undrained shear strength (su) of a clay specimen.
Some examples are Torvane (TV),
Lab Vane
(LV), and Uncon-
solidated Undrained Triaxial Compression (UUC) tests.
But
TV, LV, and UUC test suffer inaccuracies because of such
factors as:
(1)
Sample disturbance: the more disturbed the soil
structure, the lower the value of the undrained shear strength.
Sample disturbance can be caused by stress relief when making
a borehole, by hammering or pushing the sampling tube into
the clay stratum, expansion of gas during retrieval of the
sampling tube, jarring or banging the sampling tube during
transportation to the laboratory, roughly removing the clay
from the sampling tube, and crudely cutting the clay specimen
to a specific size for a laboratory test.
These actions
cause a decrease in the effective stress, a reduction in
the interparticle bonds, and a rearrangement of the soil
particles.
An "undisturbed" soil specimen will have little
rearrangement of the soil particles and perhaps no disturbance except that caused by stress relief where there is a
change from a in situ K
condition to a isotropic "perfect
sample" stress condition. (Ladd and Lambe,
1963).
A disturbed
soil specimen will have a disrupted soil structure with
23
perhaps a total rearrangement of soil particles.
The results
of laboratory tests run on undisturbed specimens obviously
better represent in situ properties than laboratory tests
run on disturbed specimens.
(2)
Strain rate: the faster a soil specimen is sheared,
i.e. a fast strain rate, the higher the value of su .
For
Torvane, Lab Vane, and UUC tests, the strain rate is very
fast with failure occuring in only a few minutes or less.
(3)
Anisotropy:
clay has a natural strength variation
where su depends on the orientation of the failure plane,
thus su along a horizontal failure plane will not equal s
along a vertical failure plane.
Lab Vane and Torvane tests
have simultaneous horizontal plus vertical failure planes
with an undrained shear strength that rarely equals s u
from a UUC test which has an oblique failure plane.
Because of sample disturbance, strain rate effects, and
anisotropy, considerable scatter in TV, LV, and UUC results
usually occurs
(for example, see Fig. 3-1).
Neglecting
anisotropic effects, an average line drawn through the s
data points in Figure 3-1 will not equal the in situ undrained
shear strength unless there is a fortuitous cancellation of
factors: i.e. the increased su due to a high strain rate is
compensated
disturbance.
by an equal reduction in su due to sample
In addition, stress-strain curves can not be
obtained from TV and LV tests, and moduli from UUC tests
are typically much too low.
24
2-2
SHANSEP METHOD
Several important symbols and there representative
definitions are presented below:
avo
a
OCR
-
in situ vertical effective stress, which equals (for
submerged soil) the buoyant unit weight (Y
times
the depth below the mudline (z) .
- maximum past pressure, obtained from the compression
curve of an oedometer test by using Casagrande's
method (see page 297 of Lambe and Whitman, 1969)..
-
overconsolidation ratio, which equals
/
Clay that is at equilibrium under the mafimmon vertical
effective stress it has ever experienced is normally
consolidated (OCR = 1.0), whereas clay that is at
equilibrium under a vertical effective stress less
than that to which it once had is overconsolidated
(OCR > 1.0).
vertical consolidation stress, for laboratory tests
vc
such as oedometer and CK0UDSS tests.
s
a
-
undrained shear strength, from strength tests such as
TV, LV, UUC, and CK 0 UDSS tests.
s /
- normalized undrained shear strength, where avc is
u vcthe vertical consolidation stress prior to shearing.
s /a
is only applicable for strength tests where
tie Ygil specimen is first consolidated to a
sheared (e.g. CK0 UDSS, Triaxial tests).
The SHANSEP
,
then
vc
method (Ladd and Foott, 1974) was developed
to obtain the stress-strain and strength properties of soft
clay deposits.
This method is based upon experience which
indicates that the in situ stress-strain and strength properties of many clay deposits are controlled by the stress
history of the deposit; for 'example, the undrained shear
strength is proportional to the overconsolidation ratio.
*
An acronym for Stress History And Normalized Soil
Engineering Properties.
25
A clay deposit must exhibit "normalized behavior" for
SHANSEP to give reliable values of su.
Normalized behavior
means that laboratory strength tests on clay specimens
having the same overconsolidation ratio will have similar
normalized stress-strain curves and identical values of
su
vc.
But naturally cemented clays and "quick clays"
have their interparticle bonds broken during the consolidation
portion of the SHANSEP laboratory strength testing technique
and thus su by SHANSEP does not represent in situ strength.
Table 2-1 presents the basic components of the SHANSEP
method.
Figure 2-1 illustrates the SHANSEP procedure to
determine the undrained shear strength profile for a uniform
clay deposit subjected to a bearing capacity failure.
The
SHANSEP method has -two distinct parts: stress history and
normalized soil properties.
Stress History
The first step in SHANSEP is to establish the stress
history of the clay deposit.
a
This means that both Q
versus depth must be ascertained (Fig. 2-la).
and
The in
situ vertical effective stress versus depth can be computed
from the index properties
(wn, S, Gs).
The maximum past
pressure data points in Figure 2-la were obtained from
oedometer tests.
the j
Knowing the -vo profile and estimating
profile from oedometer tests, the overconsolidation
ratio (OCR =
/7vo)
can then be calculated
(Fig. 2-lc).
26
A reasonably well defined stress history is essential for
reliable s values from SHANSEP.
u
Normalized Soil Properties
The second step in SHANSEP is to obtain the normalized
undrained shear strength (sU
(Fig. 2-lb).
vc ) versus OCR relationship
This consists of one-dimensionally (K0 ) consol-
idating a clay specimen in a Direct Simple Shear apparatus
beyond the in situ maximum past pressure and into the normally
consolidated region to a preshear vertical consolidation
stress
(avc ) and then shearing the specimen to obtain s /Gvc
for OCR = 1.0.
Additional CK0 UDSS specimens are consolidated
into the normally consolidated region, but then unloaded,
allowed to swell, and then sheared to obtain the normalized
undrained shear strength at varying overconsolidation ratios,
such as OCR = 2, 4, and 8.
This laboratory testing program
establishes the su /avc versus OCR relationship plotted in
Figure 2-lb.
Example of Obtaining s
by SHANSEP Method
At El. 85, the stress history results in Figure 2-la
= 7.2, an-overconsolidated
indicate that a
= 1.8 and a
vo
vm
clay with OCR = 4.0-
Laboratory CK UDSS test data plotted
in Figure 2-lb indicate that if a clay specimen has an
overconsolidation ratio of 4.0, then s /avc
= 0.60.
As
27
shown in Figure 2-ic, multiplying 0.6 times a
gives an
vo.
su = 1.08, which is plotted in Figure 2-id.
2-3
SUMMARY
The SHANSEP method will be used to determine the
undrained shear strength profiles for the Orinoco Clay at
borings El and Fl.
G s),
Knowing the index properties
(wn',
the in situ vertical effective stress ( vo) versus
depth can be computed (Chapter 3).
The stress history of
the Orinoco Clay deposit is obtained by performing oedometer
tests where the maximum past pressure (Fv)
can be deduced
by Casagrande's method and the overconsolidation ratio can
then be calculated (Chapter 5).
From Direct Simple Shear
tests run on Orinoco Clay specimens, a plot similar to
Figure 2-lb of the normalized undrained shear strength
(s /3vc)
versus overconsolidation ratio (OCR) is presented
(Chapter 6).
Then by performing the computations illustrated
in Figure 2-ic, the undrained shear strength profiles can
be drawn for the Orinoco Clay at borings El and Fl.
28
Table 2-1
SHANSEP Approach
After Ladd (1971)
Stress History And Normalized Soil Engineering
Properties Method of Estimating
Stress-Strain-Strength Properties of Clay
Generation of Data
1.
Consolidate samples to appropriate conditions
a)
If N.C. clay, use avc = 1.5 -
b)
If O.C. clay, use a
> in situ a
vm
Vc
Use K = in situ K, such as K
c)
Allow secondary compression to simulate
4 x avo
"aging".
2.
Shear samples under appropriate conditions
a)
Same stress system (Mode of failure)
(Proper a2 and rotation of principal planes)
b)
Proper strain rate
Presentation of Data
1.
Use "normalized" parameters such as su
and E/3vc; plot vs.
OCR = a
lavc
Utilization of Data
1.
Determine in situ OCR and stress system
2.
Select normalized parameter
3.
Multiply parameter by in situ avo
vc
EFFECTIVE STRESS
O
z0I.-
100------ SAND
90
2
4
8
6
ou
CKJJDSS TEST DATA
0.8
ou /(vc
-
/
AND
su
70
CLAY
0
DEPOSIT
-- e
v0o
60-
_
50 1t .
(a) IN SITU SOIL PROFILE AND STRESS HISTORY
EL. Tvo
rvm OCR
0.4
FIELD APPLICATION
[su /&,o
0.2
7.2
4.00 0.60 1.08
75
2.8
5.3
1.90 0.34 0.95
65
3.8
5.8
1.50 0.28 1.06
55
4.8
6.5
1.35 0.25 1.20
(c) COMPUTATION OF SHANSEP su VALUES
FIGURE 2 -1
, (LOG SCALE)-
OCR 0 vm (vc AND OVm '0o
(b) NORMALIZED UNDRAINED STRENGTH vs. OCR
.
1.8
vs. IN SITU lvm /dvo]
I
0'
su
85
Vs.
4-
0.6
80
UNIFORM
wj
1.0
10
z
0
UNDRAINED STRENGTH, su
0.8
1.0
1.2
1.4
to-
I-
w
(
60 -I%
(d) SHANSEP su PROFILE FOR ANALYSES
APPLICATION OF SIANSEP TO UNDRAINED STABILITY ANALYSIS USING CK U DIRECT SIMPLE
SHEAR TESTS
30
3.
INDEX PROPERTIES AND COMPOSITION OF ORINOCO CLAY
Chapter 3 begins the presentation of results from
laboratory tests upon Orinoco Clay.
Many of the laboratory
tests presented within this chapter were performed upon
clay specimens of unknown quality.
For specific gravity
tests, Atterberg Limits, X-ray diffraction tests, and
organi6 matter determinations, an initially disturbed
clay specimen should not effect the results.
However,
natural water contents and TV, LV, and UUC strength tests
can be significantly altered by sample disturbance.
3-1
UNDRAINED SHEAR STRENGTH FROM STRENGTH INDEX TESTS:
TV, LV, AND UUC
Figures 3-1 and 3-2 present undrained shear strength
(s ) values obtained by Torvane, Lab Vane, and UUC tests.
After retrieval of a sampling tube containing Orinoco
Clay, some of the soil was used onboard the Fugro ship
to perform these strength tests.
Notice the wide scatter
in results; for example, in Figure 3-1 at z = 130 feet,
2
This scatter is
s varies between 0.35 to 0.75 kg/cm .
caused by sample disturbance, strain rate effects, and
clay anisotropy (Chapter 2).
Figure 3-3 illustrates how the strain rate and sample
disturbance influence Torvane undrained shear strengths.
The Torvane tests on "undisturbed" F1S57 clay specimens
31
(open symbol,A)
is sheared
of s .
indicate that the faster the soil specimen
(i.e. a fast strain rate),
the higher the value
Standard Torvane tests usually have failure in
less than 10 seconds, and the very fast strain rate causes
about a 20% increase in s
for F1S57 clay specimens.
Torvane
tests on deliberately disturbed (remolded) clay specimens
(closed symbol,A) have much lower su values, the reduction
u2
in the undrained shear strength is from 0.5 to 0.1 kg/cm2
Figure 3-3 clearly shows that su can be reduced much more
by sample disturbance than by differences in strain rate.
Figures 3-1 and 3-2 also illustrate the effects of
different sampling techniques.
It has been stated (Wilun
et al, 1972) that "the method of forcing the sampler into
the ground has a considerable effect on the sample disturbance; samplers pushed into the soil at a fast uniform rate
produce little disturbance whereas samplers driven into
the soil with individual blows induce considerable disturbance".* At z = 60 feet in Figure 3-1 and at z = 40 feet in
Figure 3-2 there is a distinct discontinuity in the undrained
shear strength.
Above these depths,
sampling tubes were
hammered causing sample disturbance with low values of su
Below these depths, sampling tubes were pushed into the
soil strata at a fast uniform rate by using Fugro's "WIP"
sampling equipment causing less sample disturbance and
values of su more representative of the in situ undrained
shear strength.
32
3-2
INDEX PROPERTIES: NATURAL WATER CONTENT
Figures 3-1 and 3-2 also present the natural water
content (wn) for Orinoco Clay recorded onboard the Fugro
ship, at M.I.T., and at Catholic University
Venezuela for borings El and Fl respectively.
El (Fig. 3-1),
(C.U.) in
For boring
the natural water content decreases from
7S% at the mudline to 45% at a depth of 55 feet.
Below
55 feet, the natural water content increases and is constant
with depth at 53 & 2%.
Except for results from sampling
tubes ES1l2 and E1S24, good agreement exists between the
water contents determined by Fugro, C.U.,
and M.I.T.
Sampling tubes ElS12 and ElS24 contained highly disturbed
clay with very high natural water contents that probably
do not correspond to the wn of the in situ clay.
For boring Fl (Fig. 3-2),
the natural water content
decreases from 90% at the mudline to 63% at a depth of
30 feet.
Below 30 feet, the water content is essentially
constant at 65
.
5%.
Once again, good agreement exists
between M.I.T. and Fugro data except for tubes F1S54 and
F1S55 which contained highly disturbed clay.
3-3
INDEX PROPERTIES: ATTERBERG LIMITS
The results of Atterberg Limits performed by M.I.T.
and C.U. are plotted on Casagrande's Plasticity Chart,
Figure 3-4.
For boring El, the plasticity index
(P.I.)
33
ranges from 25 to 45%, classified as a CH clay.
At boring
Fl, the plasticity index above z = 70 feet is generally
40 to 50%, while below z = 70 feet, the P.I. is 50 to 65%.
The Orinoco Clay at boring Fl is classified as a CH to CHOH clay and is more plastic then at boring El.
3-4
IN SITU VERTICAL EFFECTIVE STRESS
Six specific gravity tests were performed at M.I.T.
with an average of the specific gravity of solids
(Gs
equal to 2.72 and values ranging from 2.69 to 2.74.
Table 3-1 presents data for computing the in situ
vertical effective stress at borings El and Fl.
Each
boring was divided into layers where the change in natural
water content was approximately constant;
then using wnl
with Gs = 2.72, a unit weight of salt water (y
) equal,
to 64 pounds per cubic foot, and assuming 100% saturation,
both yb and y
were calculated using the equations presented
in Table 3-1.
The in situ vertical effective stress. was
obtained by assuming hydrostatic in situ pore water pressures:
therefore avo equals depth below mudline times buoyant unit
weight (yb)'
For comparison, Table 3-1 also presents the yt values
obtained by Fugro: they weighed a sampling tube containing
Orinoco Clay, subtracted the weight of the steel liner and
then divided this value by the volume of the sampling tube.
Most values computed by Fugro are close to the
M.I.T. yt
34
calculations.
3-5
COMPOSITION ANALYSES: MINERALOGY
In mineralogy, X-ray diffraction is the process of
identifying mineral structures by exposing crystals to
X-rays and studying the resulting diffraction peaks.
X-ray
diffraction (XRD) tests on Orinoco Clay specimens reveal
the same basic types of minerals at both borings El and
Fl.
One-third to one-half of the soil consists of clay
minerals.
The clay minerals are kaolinite, illite, and
swelling minerals (smectite).
The rest of the soil contains
quartz, mica, and very weathered feldspar grains withsmall
amounts of diatom fragments, sponge spicules, and organic
matter.
Table 3-2 presents the XRD peaks for the clay minerals
S9, 515, S55,
from Orinoco Clay specimens from boring Fl.
etc. at the top of Table 3-2 refer to the sampling tubes
from which the test specimens were extracted.
The XRD peaks
for kaolin are between 40 to 50 for all specimens which
indicates that there is about the same amount of kaolinite
in all specimens tested.
from 100 to 250.
For illite, the XRD peaks vary
"Total Swelling" refers to the XRD peaks
for swelling minerals (smectite).
Except for S18, the
XRD peaks range from 100 to 225 for samples above z = 70
feet and for samples below z = 70 feet, the XRD peaks are
about double with values from 300 to 400.
A doubling of
35
the XRD peak does not necessarily imply a doubling in the
amount of swelling minerals, but it can be stated that below
z = 70 feet the clay contains considerably more swelling
minerals.
This discovery is very important because swelling
minerals have profound effects upon engineering properties.
Unfortunately, only four mineralogy tests were performed on
boring El specimens and, as shown -if Table 3-3, an increase
in swelling minerals below z = 70 feet is not indicated by
the scant data.
3-6
SALT CONCENTRATION AND ORGANIC MATTER
As shown in Figure 3-5, the salt concentration of the
pore fluid for both borings El and Fl decreases with depth
from 35 grams/liter at the mudline to 25 + 5 grams/liter
at z = 130 feet.
The salt concentration woild -be expected
to be 35 grams/liter for the entire deposit since the
Orinoco Clay has been deposited in salt water.
Perhaps
the reduction in salt concentration with increasing depth
is caused by chemical diagenesis.
The pore fluid, incompatible
and/or unstable minerals (feldspar grains), organic matter,
and carbonates interact with each other to bring the soil
into equilibrium, perhaps causing the salt concentration to
decrease with time.
Figure 3-5 also presents the percentage of the soil
mass that is organic matter.
The organic matter content
is very small, 2 + 0.5%, but it does decrease slightly
36
at depths greater than 100 feet.
3-7
SUMMARY
In Figures 3-1 and 3-2 there is considerable scatter
in the undrained shear strength from TV, LV, and UUC tests.
A distinct discontinuity exists in the undrained shear
strength data at z = 60 feet in Figure 3-1-and at z
40
feet in Figure 3-2 caused by different sampling techniques
where hammering a sampling tube causes more sample disturbance than Fugro's "WIP" sampling procedure.
The Orinoco Clay at boring El is classified as a CH
clay and has a P.I. between 25 to 45%.
The Orinoco Clay
at boring Fl'is classified as a CH to CH-OH clay with a P.I.
between 40 to 50% above z = 70 feet, while below z = 70
feet, the P.I. is 50 to 65%.
Mineralogy results indicate that the Orinoco Clay at
both borings El and Fl contains the same basic minerals;
one-third to one-half of the soil being clay minerals such
as kaolinite, illite, and swelling minerals
(smectite).
The rest of the soil consists mostly of quartz, mica, .and
weathered feldspar grains.
For boring Fl, there is consid-
erably more swelling minerals below than above z = 70 feet.
UNIT WEIGHTS AND EFFECTIVE STRESS
TABLE 3-1
Y
Depth
(ft)
Boring
El
(t
VN
(1)
(2)
Ave. i
ai
a0
SD
(M)
0-55
59
105.2
101.6 ± 8.2
55-75
49
110.0
105.0 t 1.4
-0.129
0.0225
75-140
52
108.4
107.1 ± 5.8
-0.0703
0.0217
0-30
77
98.8
94.2 ± 4.0
0
0.0170
30-140
63
103.6
104.4 ± 9.4
-0.0703
0.0193
Yt= GsYw (1 + wn)/(I + wnGsywysw)
avo
(tube)
pcf
-
(pcf)
Fl
Yb
Parameters
FUGRO
Assumed
t
0.0201
0
Assuming 100% saturation
sw
b(z)
Assuming hydrostatic in situ pore water pressures
Using the above
yt equation, with Gs = 2.72, y w = 62.4 pcf, and y
Svo(kg/cm2) = a0 + a1Z(ft)
= 64 pcf
TABLE 3-2
CLAY MINERALOGY SUMMARY FOR BORING Fl
Absolute Peak Amplitude
Phase
S9
(27')
S15
(51')
S55
(66')
S18
(66')
S24
(96')
S27
(111')
S57
(127')
W~h
co
Kaolin
45
45
40
40
40
50
45
Illite
200
120
100
200
250
200
220
Total Swelling
225
200
100
400
400
300
400
TABLE 3-3
CLAY MINERALOGY SUMMARY FOR BORING El
Absolute Peak Amplitude
(55')
(83')
S21
S27
(99')
(134')
Kaolin
50
40
50
40
Illite
150
120
250
120
Total Swelling
270
190
250
210
PhseS15
Phase
S18
MIT
WN (%)
SAMPLES
40
0
50
60
su (TSF, kg /cma)
0
Rfl
70
0.2
0.8
0.6
0.4
e x
cD
FUGRO
t
00
20
20
XV*
40[ 512
104
0
xe
40
some0
x
S5
-
00
0
0
am0 a
S18
LAB VANE
0
uuc
e>
0
80
0
-o
0
x ()p
i3
0
K
00
x
100 -S21
100
0
0
S24
0
60
K
0
120
O FUORO
* MIT
0 1o
S27
0
C --
T
WIP
00
80
TORVANE
x 6
4..
Id
0
x
C
-0
C.u.
0
120
K
00
x
S
140L
-1 -
FIGURE 3-1
NATURAL WATER CONTENT AND STRENGTH INDEX TESTS: BORING El
401-
6 0
00
l.0
Mil
SAMP LES
50
0
su (TSF, kg/cma)
WN N
60
80
T
90
100
0
0.2
0
0
S54 (WIP)
S12
401
S15
4-
0
0
APXx
00a_
___
00
T
0
SIB
I--
o
_
0
1V24
FIGURE 3-2
_
_
_
X0
0
0
C
100
X
C
0
S27
140L
_
x
0
0
0
3001-
O
__
80
0
[S57
e
H1
00
1530
LAB VANE
40
80 -21
1201
C
0
60
00
S55
TORVANE
uuc
e
40
X
,0
WIP
0
60
FUGRO
20
o
0.1
0.6
C
0
20
0.4
00
C
x
120
0
0
>O
.
00
0 FUGRO
x
ex'
0 MIT
140
A
NATURAL WATER CONTENT AND STRENGTH INDEX TESTS; BORING Fl
A
1
C
0.50
A
I
- 0.40
0.30
A
ra)
N)J
A
0.20
A
0.10
z
Sample F1S57
= 129 ft
A - "UNDISTURBED" CLAY
A
-
REMOLDED CLAY
ONBOARD TV
0
0
20
40
60
80
=
0.48 kg/cm 2
100
TIME TO FAILURE (SECONDS)
FIGURE 3-3
EFFECTS OF DISTURBANCE AND STRAIN RATE ON TORVANE DATA: SAMPLE F1S57
0
70
OIN -ET
-
-f
-0
600
O>NG
00
DT
50I
0__
(i.__
00.
__
__
o20
() By C.U.ALL OTHER DATA BY MIT
40
III
200
U)
20
0
10
20
30
40
50
60
LIQUID LIMIT, wL ()
FIGURE 3-4
PLASTICITY CHART: ORINOCO CLAY
70
s0
so
IOU
ilu
ORGANIC MATTER (%)
SALT CONCENTRATION (g/l)
20
15
IC
o
-
30
25
35
0
2
I
3
I
El 0
20
FI O
0
I _
40
0
00
I__ -1_0_
0
I
60
0
0
w 80
a
100
l
(20
0
0
120
00
FIGURE 3- 5
SALT CONCENTRATION AND ORGANIC MATTER: ORINOCO CLAY
'9
M
0
45
4.
4-1
RADIOGRAPHY
INTRODUCTION: X-RAYS
In 1895, Wilhelm Konrad Roentgen discovered X-rays,
which are one form of electromagnetic radiation.
Other
examples of electromagnetic radiation are radio waves and
visible light where a distinguishing characteristic is .the
wave length; defined as the distance, measured in the direction of propagation of the wave, between two successive
peaks.
The approximate wave lengths for X-rays and visible
light are 100 millionths and 20 thousandths of a centimeter
respectively, while radio waves have wave lengths that vary
between a meter to several kilometers in length.
The fact
that X-rays have wave lengths that are 5,000 times smaller
than those of visible light accounts for the penetration
through metals by X-rays compared to the reflection or
absorption of light waves.
X-rays are produced when electrons traveling at high
speeds collide with matter.
The kinetic energy of a high
speed electron is transferred into heat and X-ray photons
as it strikes the nucleus of a stationary atom.
One
mechanism that produces X-ray photons is the cathode ray
tube.
Photography using X-rays is called radiography.
A
radiograph is the photographic record produced by the
passage of X-rays through an object and onto a white photo-
46
graphic film.
If silver halide crystals are placed upon
a white photographic film and then bombarded with X-rays,
the chemicals will react with X-ray photons causing the
photographic film to darken.
As X-ray photons travel
through a solid medium, some photons will be absorbed and
the denser a material the more photons absorbed.
For
example, a radiograph produced after positioning a man's
chest between an X-ray source and a photographic film will
distinctly reveal the bones of the chest cavity which are
much denser than the surrounding flesh, tissue, and organs.
4-2
DESCRIPTION OF M.I.T.'s RADIOGRAPH FACILITY
M.I.T. received radiograph facilities for use in
geotechnical engineering research by a N.S.F. equipment
grant (number ENG78-10435).
The facilities include:
(1) a X-ray source generator containing a double
beryllium window,
(2)
a constructed enclosure 12 feet by 8 feet by 7
feet containing lead shielding on all walls, and
(3) a dark room to develop the radiographs.
The major advantage of radiography is that a photograph of the soil can be obtained before the soil is
extruded from it's sampling tube.
Worm holes, coral
fragments, cracks and gravel inclusions can easily be
identified by -using radiography (e.g. Allen et al., 1978).
Photons contain energy with zero mass and thus X-rays
47
can not displace or disturb soil particles.
X-rays can
kill organisms, for example bacteria, fungi, etc. living
within the soil mass, but the lethal dose for such organisms is several orders of magnitude greater than that
induced during radiography.
A sampling procedure using thin-walled cylindrical
sampling tubes was utilized to obtain Orinoco Clay.
The
sampling tubes are stainless steel having a thickness of
0.1 inch with an outside diameter of 3 inches.
Tubes
were two to three feet long with both ends sealed with
approximately two inches of wax.
Hitherto, the only means
of examining the clay was to extrude it from the tube.
Because the sampling tubes are cylindrical, X-rays
that strike at the center of the tube (point A, Fig. 4-la)
must travel through 0.2 inches of stainless steel and 2.8
inches of soil, while those X-rays that strike at point B
(Fig. 4-la) travel through much less soil.
The density
at point A is much greater than the density at point B and
aluminum plates of varying thickness are arranged so that
the density across the tube is approximately uniform.
vertical lines in the radiograph prints
The
(for example, see
Fig. 4-3) are caused by the varying thickness of the
aluminum plates.
Some X-ray photons are reflected off the walls and
these photons could strike the photographic film from behind.
To eliminate this scatter radiation, lead shielding is
48
positioned behind and around the photographic film (Fig.
4-1).
The variables for the radiography of sampling tubes
are the input voltage and current to the X-ray source, the
duration of X-ray bombardment of the photographic film,
the distance from the X-ray source to the photographic
film, and the developing time of the photographic film.
After numerous trials, the following values produced the
best radiographs for 3 inch diameter sampling tubes:
4-3
Input Voltage:
160 kilovolts
Input Current:
3.9 milliamperes
Exposure Time:
5 minutes
Distance From X-ray Source:
6 feet
Developing Time:
15 minutes
RADIOGRAPHY OF SAMPLING TUBES CONTAINING ORINOCO CLAY
This'section will present radiograph prints, that have
been reproduced as positives using the radiograph as.a
negative, of Orinoco Clay within sampling tubes.
Light
areas represent zones of low soil density and dark areas
represent zones of high soil density.
The radiograph
prints are close to true scale.
Sampling Tube F1S57, Sample Disturbance
Figure 4-3 is a radiograph print of the top 10 inches
of sampling tube F1S57 (depth = 127 to 130 feet).
Lead
49
numbers
(0 through 9) and letters
(A, B, C, etc.) were usually
attached at one inch nominal distances along each tube and
radiographs taken at 10 inch intervals, which is the size of
the photographic film.
The top of Figure 4-3 at letter E is the top wax seal,
which has a very low density.
As the Orinoco Clay was
extruded from sampling tube F1S57, Torvane and engineering
tests were performed and the results are presented in Figure
4-2.
Several important conclusions can be obtained by
comparing Figure 4-2 with Figure 4-3.
(1) Figure 4-3 illustrates a swirling mass of clay
containing large voids.
The clay between letters Z to U is
highly disturbed with Torvane undrained shear strengths
less than 0.1 kg/cm2 .
Possibly this highly disturbed clay
is cuttings inadvertently left at the bottom of the borehole.
Some of the disturbance could also be caused by
tube friction during sampling as the clay near the tube
wall may become remolded as it travels up the tube.
(2) In Figure 4-3, the Orinoco Clay below letter U
is uniform in appearance and does- not contain voids.
Figure 4-2 indicates that between letters U to S the
Torvane undrained shear strength increases from 0.1 to
2
0.5 kg/cm2.
Below letter S, the Torvane undrained shear
strength is constant at 0.5 kg/cm2 and this value is very
close to the Torvane strength obtained onboard the Fugro
ship.
50
(3) The Orinoco Clay between letters T-S appeared to
be of excellent quality when viewing Figure 4-3 and was
used for oedometer test No. 12
(oed-12).
The oedometer
results indicated that the Orinoco Clay at this depth of
127.7 feet was underconsolidated (OCR = 0.56).
The Torvane
undrained shear strengths obtained directly above the
oedometer specimen were considerably less than the Torvane
s
value obtained onboard the Fugro ship (0.3 versus 0.48
kg/cm2).
The lower Torvane su value of 0.3 kg/cm2 was
caused by sample disturbance and the clay specimen for the
oedometer test No. 12 was also disturbed resulting in a low
maximum past pressure and subsequent low OCR.
A new
oedometer test was performed on a better quality specimen
(Oed-18, see Fig 4-2) and the results indicated a slightly
overconsolidated deposit
(OCR = 1.15).
In this instance,
only the radiograph was used to select oedometer test No.
12 specimen, yeti comparing the Torvane undrained shear
strength obtained above the oedometer specimen (TVoed)
to the Torvane strength obtained onboard the Fugro drilling
ship (TVboat
would have provided an additional assurance
of a good quality specimen.
Sampling Tube ElS12, Gas Pockets
Figure 4-4 is a radiograph print of a 10 inch portion
of tube ElSl2
(depth = 37 to 40 feet).
The white specks
dispersed throughout the print represent voids.
The voids
51
probably. occurred- when air and -hyarogen sulfide gas
(H2 S)
came out of solution as the in situ confining pressure was
reduced to zero during retrieval of a sampling tube.
As
the dark gray Orinoco Clay was extruded from tube ElSl2,
a pungent odor of rotten eggs assailed one's senses.
The
clay was exceedingly soft, it was closer to a viscous liquid
than a solid, and it possessed negligible shear strength
(Torvane readings were zero).
Tubes ElS24
(depth = 113 to 116 feet), F1S54
25 to 27 feet), and F1S55
(depth = 65 to 67 feet) had
similar looking radiographs
(voids).
(depth =
that contained white specks
Upon extrusion from the sampling tubes,
the
Orinoco Clay was highly disturbed with low Torvane strengths
and high natural water contents.
Sampling Tube ElS21, Horizontal Cracks
Figures 4-5a and 4-5b are radiograph prints of tube
ElS21 (depth = 98 to 100 feet).
The Orinoco Clay at the
top of Figure 4-5a was disturbed with very low Torvane
undrained shear strengths.
The bottom of Figure 4-5a
shows numerous horizontal cracks, probably the result of
gas coming out of solution.
At the top of Figure 4-5b,
the horizontal cracks diminish in number with excellent
quality soil between letters E through I.
Radiograph
prints can also reveal the type of soil structure, e.g.
in Figure 4-5b the clay has a slightly layered appearance.
52
Figures 4-5a and 4-5b clearly demonstrate the value
of using radiography to select zones of good quality soil
Only a small portion of the Orinoco
for laboratory tests.
Clay within sampling tube ElS21 was suitable for the
sophisticated engineering tests.
All the Orinoco Clay
above letter E was extruded and used for index tests, then
the good quality clay between letters E through I was
extruded and used for oedometer, triaxial, and CK0 UDSS
tests.
4-4
SUMMARY
Radiography is an invaluable tool that can be used to
detect those portions of soil within the sampling tubes
least likely to be disturbed and hence most suitable for
sophisticated laboratory tests such as oedometer and Direct
Simple Shear tests.
The radiograph prints presented
within this chapter clearly show several important features:
(1) Zones of disturbed Orinoco Clay due to:
(a) possible cuttings inadvertently left at the bottom
of the borehole and/or highly remolded soil
(Fig. 4-3),
and
(b) expansion of gas pockets as the gas comes out of
solution upon release of in situ confining pressures
(Fig.
4-4).
(2) Zones containing horizontal cracks, presumably
caused by expanding gas
(Fig. 4-5)
53
(3) Different soil structure; for example, very
uniform (bottom of Fig. 4-3) or slightly layered (middle
of Fig. 4-5b).
The radiograph prints clearly indicated the proportion
of "good-excellent" quality clay to that of disturbed soil.
Thus radiography enables the geotechnical engineer to locate
the best quality clay before extruding the soil from the
sampling tube.
This aids in planning a soil testing program
and reduces the likelihood of performing meaningless laboratory tests on severely disturbed soil.
54
RADIOGRAPH FILM
ALUMINUM
B
PLATES
TUBE SAMPLE
NOTE: TARGET AREA
SURROUNDED BY
LEAD SHIELDING
X-RAYS
X-RAY HEAD
(a) ELEVATION VIEW
RADIOGRAPH FILM
10 IN.
TUBE
SAMPLE
6
F
ALUMINUM
PLATES
.
X-RAYS
EJ X-RAY
(b) PLAN VIEW
FIGURE 4-1
HEAD
NOT TO SCALE
RADIOGRAPHY OF A SAMPLING TUBE CONTAINIUG ORINOCO
CLAY
MARKINGS
I
w
2
su (kg/cm )
TUBE
WAX
127.01(1)
N
0.2
0.4
0.5
0 uuc
(2) EST. TVO= 2.40
0
0.3
0 TORVANE
STRESSES IN kg/cm 2
(3) ONBOARD
127.51-
0.1
NOTE:
VOID
01-
0
ENGINEERING
TESTS
TV=0.48
0
444
UUc No. 4
w
a
L,
u,
su =0.14
>0
0z
WN=72.2 %
(I)
OED No. 12, wN=
6 4 .8
%
vm =1.35, CR=0.25
128.0O
66
OED No. 18, WN= .5 %
Ivm=2.75, CR=0.36
z
FIGURE 4-2
OEDOMETER AND STRENGTH DATA ON SAMPLE FlS57 FOR COMPARISON WITH RADIOGRAPH-
E
U51
M~
FIGURE 4-3
SAMPLE F1S57:
RADIOGRAPH
PRINT SHOWING SAMPLE DISTURBANCE
(from Ladd, et al. 1980)
uL
FIGURE 4-4
SAMPLE ElS12:
RADIOGRAPH PRINT SHOWING GAS POCKETS
(from Ladd, et al. 1980)
FIGURE 4-5a
SAMPLE ElS21:
RADIOGRAPH
PRINT SHOWING HORIZONTAL CRACKS
(from Ladd, et al. 1980)
FIGURE 4-5b SAMPLE ElS21:
RADIOGRAPH
PRINT SHOWING HORIZONTAL CRACKS
(from Ladd,
et al.
1980)
60
STRESS HISTORY AND CONSOLIDATION PROPERTIES
5.
5-1
INTRODUCTION: TEST PROCEDURES FOR OEDOMETER TESTS
Seventeen oedometer tests were performed on Orinoco
Clay specimens in the M.I.T. geotechnical laboratory,
five from boring El and twelve from boring Fl.
The
procedures used for all oedometer tests are the same
as those described in Lambe (1951), except as noted
below:
(1) The oedometer tests were performed with a load
increment ratio equal to 1.0, except near the presumed
maximum past pressure where it was reduced to approximately
0.5 in order to better define the maximum curvature-of the
compression curve.
(2)
The maximum past pressure was obtained by using*
Casagrande's method (Casagrande, 1936) for compression
curves based on vertical strain (Ev) versus vertical consolidation stress (7vc), where the vertical strains are those
corresponding to the end of primary consolidation (Ladd
1973).
The load increments were applied for a time interval
of sufficient duration to enable the determination of the
end of primary consolidation.
Oedometer Orinoco Clay specimens were cylindrical,
2.5 inches in diameter and approximately 1.0 inch in height.
During testing, the clay specimens were continuously
surrounded by distilled water in the oedometer apparatus.
61
Some of the dissolved salt in the pore fluid of the clay
specimen will diffuse into this distilled water.
To
investigate whether or not a change in the pore fluid
salt concentration will effect engineering properties,
two Atterberg Limits were performed on ElS15 clay specimens
where the liquid limit was 63% for an original specimen
having a pore fluid salt concentration of 29 grams/liter
and when the pore fluid salt concentration was diluted to
1 gram/liter, the liquid limit was essentially unaltered
(64%).
Since a significant reduction in the pore fluid
salt concentration does not alter liquid limits, then the
small change in pore fluid salt concentration during an
oedometer test should not effect the result's.
Table 5-1 summarizes all oedometer results for boring
El and Table 5-2 for boring Fl.
Both tables present the
following data:
(Column 1) Depth of oedometer specimen and sample
tube number.
(Column 2) Oedometer test number.
(Column 3) The natural water content and the Atterberg
Limits for each oedometer test as measured from test
specimen trimmings.
(Column 4) Two sample disturbance indices;
TV(oed/boat)
is the ratio of Torvane undrained shear strength obtained
directly above the oedometer specimen to that recorded
onboard the Fugro ship during sampling operations, and also
62
the vertical strain (e ) during recompression to
'
(Column 5) The in situ vertical effective stress ( vo)
using the equations presented in Table 3-1.
(Column 6) Best estimate (along with a range) of the
maximum past pressure determined by the Casagrande method.
(Column 7) Virgin compression ratio
(CR), defined as
the slope of the vertical strain versus log consolidation
stress in the normally consolidated region.
Swelling ratio
(SR), defined as the average slope, over one log cycle, of
the rebound curve starting from the maximum consolidation
stress.
(Column 8) Average coefficients of consolidation
(c
determined from the dial reading versus log time and square
root time curves, in the normally consolidated region.
(Column 9) The rate of secondary compression
(Ca
defined as the slope of the secondary compression line
from a log time curve, in the normally consolidated region.
(Column 10) An assessment of the quality of each
oedometer specimen (excellent, good, fair, or poor) based
on it's
disturbance indices,
TV(oed/boat)
and Ev at avo'
and the general appearance of the compression curve
sharp break at a
5-2
(e.g.
, etc.).
EFFECTS OF SAMPLE DISTURBANCE
This section will discuss how sample disturbance
effects oedometer results by comparing Oed No. 12 and
63
Oed No. 18
(specimens from sampling tube F1S57).
discussed in Chapter 4, Oed No.
As
12 was disturbed and had
significantly different engineering properties than Oed
No. 18, yet the clay specimens were within two inches of
each other
From Table 5-2, the ratio
(see Fig. 4-2).
TV(oed/boat) for Oed No. 12 is 0.63, while for Oed No.
18
the value is 1.06.
Figure 5-1 presents the compression curves and values
of the coefficient of consolidation for Oed No. 12 and
Oed No. 18.
By comparing these two oedometer tests, we
can observe the effects of sample disturbance:
(1) An increase in the measured vertical strain for
disturbed specimens.
The vertical strain during recom-
pression to -vo is 11.3% for Oed No. 12, but only 5.5%
for Oed No. 18.
(2) A reduction in the maximum past pressure for
disturbed specimens.
. 1
Oed No. 12 has a
while for Oed No. 18, F
2.
= 2.75 kg/cm2.
2.4 kg/cm2, the results of Oed No.
consolidated clay deposit
-
2
= 1.35 kg/cm2
Because a
=
12 indicate an under-
(OCR = 0.56) but the results
for Oed No. 18 indicate a slightly overconsolidated deposit
(OCR = 1.15).
(3) Sample disturbance caused a reduction in the
virgin compression ratio
(CR).
The value for CR is 0.245
for Oed No. 12 and 0.355 for Oed No. 18.
Sample distur-
bance has caused a 30% reduction in the virgin compression
64
ratio.
(4) During recompression to %vo' the coefficient of
consolidation (c ) is less for disturbed specimens. At
-4 2
2
avc = 0.75 kg/cm2, Oed No. 12 has a c
but Oed No. 18 has a cv = 11.5 x 10
= 3 x 10
-4 2
cm /sec.
cm2/sec,
Sample
disturbance does not effect c. in the normally consolidated
region where both Oed Nos. 12 and 18 have cv = 2 x 10 4 cm 2 /sec.
(5) Oed Nos. 12 and 18 have rebound curves that are
almost parallel.
The swelling ratio (SR) was not altered
by sample disturbance.
It must be reemphasized that Oed No. 12 was disturbed
and this caused the significant difference in engineering
properties between Oed No. 12 and Oed No. 18.
An excellent
quality specimen was used for Oed No. 18, and the results
of this test better represent the in situ soil properties
(e.g. -
, CR, etc.).
Figure 5-2'presents the oedometer disturbance indices
TV(oed/boat) and ev at 'vo for all oedometer tests .performed
at M.I.T.
As previously discussed, disturbed specimens
will have a TV(oed/boat) ratio less than 1.0, a high value
of ev at avo, and a low value of av
OCR.
with a subsequent low
In Figure 5-2, the undisturbed or slightly disturbed
specimens are open symbols (e.g. [, 0) and the disturbed
specimens are closed symbols (e.g.E,@0).
The radiographs
enabled what appeared to be good quality specimens to be
chosen for oedometer tests, yet the disturbance indices
65
presented in Figure 5-2 indicate that 5 out of the 17
oedometer tests were performed on disturbed specimens.
5-3
STRESS HISTORY
Figure 5-3
(similar to Fig. 2-la) presents a plot of
in situ vertical effective stress
(Fvo) versus depth for
borings El and Fl using the equations presented in Table
3-1.
A specific gravity of 2.72, a degree of saturation
of 100%, and hydrostatic pore water pressures were used
to compute jvo at both borings El and Fl.
The difference
between the two Ivo profiles is caused by the different
natural water contents at each site, e.g. at z = 40 feet,
wn = 54% at boring El and wn = 60% at boring Fl.
Maximum past pressure data from Tables 5-1 and 5-2
are also plotted in Figure 5-3.
The open symbols for
borings El and Fl suggest that these deposits both have
the same maximum past pressure profile and the dashed
straight line is a reasonable linear fit
points.
through the data
Considering only the oedometer tests upon
excellent-good quality specimens, the overconsolidation
ratio is approximately 1.0 for boring El and 1.15 for
boring Fl.
A normally consolidated deposit (OCR = 1.0)
is what would be expected for the offshore Orinoco Clay
since the mudline has always been below sea level and
the deposit has a recent depositional history.
An
overconsolidation ratio of 1.15 at boring Fl is difficult
66
to explain since essentially the same geologic conditions
are believed to exist at both borings El and Fl.
Since
boring Fl is exposed to larger ocean waves than boring
El (see Fig. 1-1),
the very small amount of overconsolidation
could be caused by wave induced cyclic shear stresses
(Madsen, 1978).
However, the author doubts that these
shear stresses could create a uniform OCR of 1.15.
The
author has no rational explanation for the slightly overconsolidated clay at boring Fl.
5-4
COMPRESSIBILITY AND COEFFICIENT OF CONSOLIDATION
Figure 5-4 presents the virgin compression ratio (CR),
swelling ratio
(SR), and normally consolidated coefficient
of consolidation (cv) versus depth for borings El and Fl.
Considering only the excellent-good oedometer data, the
virgin compression ratio, swelling ratio, and coefficient
of consolidation have significantly different values above
than below z = 70 feet.
Suggesting a distinct boundary
at z = 70 feet is only for convenience, since a transition
zone of engineering properties probably exists between
z = 60 to 80 feet.
Appendix A contains the laboratory data from consolidation tests and a summary of oedometer results is
presented in the following table:
67
STRESS HISTORY AND CONSOLIDATION PROPERTIES
Boring Fl
Boring El
-1
z<70 ft
t
z>70
ft z<70 ft I z>70 ft
Slightly
Overconsolidation
Normally
Ratio (OCR)
Consolidated
Overconsolidated
Virgin Compression
iriCor0.19
0.30
0.22
0.33
Swelling
Ratin(R)0.03
0.05
0.04
0.08
2x10 4
5x10
2x10
Ratio
Ratio
(CR)
(SR)
N.C. Coefficient of
Consolidation
2
(c ) in cm /sec
7x10
As shown in the preceding table, the values of CR,
SR, and cv are almost identical at both borings El and
Fl but different above and below z = 70 feet.
In Table
3-2, mineralogy data for boring Fl indicate considerably
more swelling minerals below z = 70 feet.
The doubling
of the swelling ratio (SR = 0.04 versus 0.08)
below
z = 70 feet is caused by the increase in swelling minerals.
Also, the author believes that the higher compressibility
(CR = 0.22 versus 0.33) and lower normally consolidated
coefficient of consolidation (cv = 5 x 10-4 versus 2 x 10-4
cm2/sec) is caused by the increase in swelling minerals
below z = 70 feet.
68
5-5
EMPIRICAL CORRELATIONS
Figures 5-5 and 5-6 compare data obtained from the
oedometer tests versus some empirical correlations published
in the literature: Nishida (1956), DM-7
and Peck (1967).
(1971), and Terzaghi
There is considerable scatter in both
figures, but the data are distributed symmetrically above
and below the empirical correlations.
Thus, the empirical
correlations derived for the most part from land based clays
are also applicable for the offshore Orinoco Clay.
SUMMARY
5-5
As shown in Figure 5-3, the Orinoco Clay at boring
El is normally consolidated (OCR = 1.0) and at boring
Fl it is slightly overconsolidated (OCR = 1.15).
Similar
geologic conditions exist at both borings El and Fl which
suggests that both deposits should be normally consolidated.
The author has no rational explanation for the slightly
overconsolidated clay (OCR = 1.15) at boring Fl.
At both borings El and Fl, two distinct zones of
Orinoco Clay exist, one above and the other below z = 70
feet.
The virgin compression ratio for the Orinoco Clay
above z = 70 feet is 0.19 at boring El and 0.22 at boring
Fl, while below z = 70 feet the Orinoco Clay is much more
compressible, CR equals 0.30 at boring El and 0.33 at
boring Fl.
A considerable increase in the swelling
minerals is probably the cause of the different consolidation properties below z = 70 feet.
TABLE 5-1
All stresses in kg/cm2
z(ft)
(Sample)
SUMMARY OF OEDOMEIER TEST DATA:
(A)
BORING El
TESTS PERFORMED AT MIT
Oed.
WN
PI
WL
LI
TV(Wd/Boat)
(ev at 5 )
Est. 'Uvo
Test No.
Est. Uvm
CR
(Range)
(SR)
Normal
6 (10~
cm
Consolidated
/sec) Ca(Z)
Remarks
55.7
(S15)
1
48.1
32.5
58.0
69.5
1.75,
(6.50)
1.12
1.3
(1.1-1.5)
0.190
(RR-0.031)
7.1510.15
0.55
Good
83.3
(S18)
2
63.1
42.7
74.0
74
0.94
(10.50)
1.74
1.6
(1.5-1.7)
0.260
(RR-0.060)
3.0010.30
0.83
Poor
99.3
3
52.7
64.8
1.14
2.08
0.300
2.95±0.05
0.94
Good
31.5
62
(6.50)
(S21)
2.2
(2.1-2.3)
6
(RR=0.05 )
133.8
(S27)
13
54.6
39.4
76.5
44
1.04
(6.40)
2.83
2.9
(2.8-3.0)
0.300
(0.053)
1.9010.40
1.04±0.35
Good
133.9
(S27)
14
53.5
39.4
76.5
42
1.04
(6.40)
2.84
2.8
(2.7-2.9)
0.300
(0.051)
2.80±0.50
0.6010.07
Good
(B)
75
(S16B)
56
41
70
66
125.5
(S25C)
52
38
65
66
145.5
(S29D)
55
40
73
55
TESTS PERFORMED AT CATHOLIC UNIVERSITY,
1.56
2.65
3.11
CARACAS
1.35
(1.3-1.4)
0.32
(0.038)
0.60t0.20
-
Fair
1.8
(1.7-1.9)
0.25
(0.077)
3.00±2.00.
-
Poor
3.0
(2.7-3.3)
0.30
(0.046)
5.001.00
-
Fair
TABLE 5-2
All
SUMMARY OF OEDOMETER TEST DATA:
BORING Fl
stresses inrkg/cm 2
Normally Consolidated
TV(Oed/Boat)
(ev at -a.)
Est. 4v
z(ft)
(Sample)
Oed.
Test No.
WN
UL
PI
LI
27.2
(S9)
5
63.5
46.6
81.8
61
1.27
(4.2)
0.46
0.55
(0.45-0.65)
0.205
(0.035)
4.7310.95
0.55±0.10
Good
36.6
(S12)
9
63.3
43.7
80.0
62
1.43
(4.8)
0.64
0.75
(0.70-0.80)
0.230
(0.045)
5.43±1.09
0.67±0.03
Excellent
51.6
(S15)
11
66.2
57.5
96.5
47
0.75
(5.3)
0.93
1.00
(0.90-1.10)
0.245
(0.055)
5.18±1.36
0.53±0.11
Fair
66.7
(s18)
4
64.1
47.9
80.7
65
1.09
(6.4)
1.22
1.50
(1.40-1.60)
0.305
(0.060)
4.73±0.96
0.54±0.08
Excellent
81.5
(S21)
8
67.0 104
64.9 43
1.07
(8.0)
1.50
1.85
(1.70-2.00)
0.315
(0.075)
4.00±0.55
0.89±0.08
Good,"Platy"
Structure
96.3
(S24)
6
62.5
51.2
87.5
51
1.06
(5.1)
1.79
2.40
(2.30-2.50)
0.255
(0.060)
7.10±2.22
111.4
(S27)
10
66.5
48.3
90
51
0.82
(6.3)
2.08
2.00
(1.90-2.10)
0.310
(0.070)
3.10±0.75
0.75±0.05
Poor
111.8
(S27)
17
68.3
56.4
93.0
56
1.22
(5.2)
2.09
2.20
(2.10-2.30)
0.325
(0.080)
3.50±0.45
1.0010.24
Good
126.2
(S30)
7
59.8 101.8
67.8 38
0.68
(11.3)
2.37
1.60
(1.50-1.70)
0.260
(0.090)
2.33±0.51
0.75±0.11
Poor
126.5
(S30)
16
65.0
55.4
96.0
44
0.97
(4.9)
2.37
2.80
(2.70-2.90)
0.330
(RR=0.075)
2.55±0.35
0.820.03
Excell.-good
127.8
(S57)
12
64.8
57.1
99.0
40
0.63
(11.3)
2.40
1.35
(1.25-1.45)
0.245
(0.085)
2.15±0.13
0.84±0.15
Poor
128.0
(S57)
18
66.5
57.1
99.0
43
1.06
(5.5)
2.40.-
2.75
(2.65-2.85)
0.355
(0.0900)
2.08±0.48
1.0510.18
Excell.-good
Est.UVM
(Range)
CR
(SR)
Remarks
Cv(10:4cm2/s1ec) Ca(Z)
0.5310.13
Excellent
'Platy"Struc.
.4
0
71
5
__
m2.75
_vm
10
.
15
U,
20
SYM.
TEST
No.
(%)
wN
TV
(TSF)
is
66.5
0.51
12
64.8
0.30
0
0
2
0
0.1
c-
0.2
5
0.2
12
10
1~- bi1
0
C(n
z
0
E
u c*00)
0
E
1
z
8
-8
w
0
uL
0.1
0.2
0.5
1
2
CONSOLIDATION STRESS, Tc
FIGURE 5-1
5
10
(kg/cm2 )
EFFECTS OF DISTURBANCE ON OEDOMETER TEST DATA:
SAMPLE F1 S57
TV (OED)/(BOAT)
0.4 0.6 0.8
01
1
1
1.0
1.2 1.4
I
I
I
E6
1.6
0
2
(%) AT Mo
4
6
8
10
OCR a (m
1214
BORING
EXCELLr
GOOD
FAIRPOOR
El
0
0
U
cu
Fl
.4 0.6 0.8
1T.o
1.0 1.2
1.4
1.6
__
0
-
0-~
--
-
0
400
0
1.75
60
-
0
0
-4
Is.)
(-
-
0
0100
-
--
---
--
120
-
0
- -
0
0
*
-----
0
00
00
-
o
0(2 TESTS)
0(2 TESTS)
I
FIGURE 5-2
OEDOMETER
@0
T
I
I
TEST DISTURBANCE INDICES:
I
ORINOCO CLAY
(r.0 AND Tvm (kg /cm?)
0
0.5
2.0
1.5
1.0
BORING
BY
EXCELLGOOD
cu
_
TEST
MIT
0
l
MIT
0
40
60
3-
_ _O(FI)
100
o (E1)
120
140
I
FIGURE 5-3
I
STRESS HISTORY:
ORINOCO CLAY
FAIRPOOR
_
20
4 0F
a.
0
4.0
3.5
3.0
2.5
U
_
_
_
SRa C /(I+e)
CR= Cc/(1+e)
020
0.30
025
EXCELL7
GOOD
FAIRPOOR
El
0
U
Ft
0
.
BORING
--
20
-----
-
0.40
0.35
005
4
n
0.J0
4
C, (10 cm/sec)
10
5
0
NOTE: AVE. FROM AND LOG t METHODS
IN N.C. RANGE
0
0
-
-
-
40 -
0
-
VF
0._00
__
60
0
-.1
C
0
-
N%
-
80
00
---
1
0--+
-
t -- 'I___
__1
120
0 0
0 .
-0----
04
0
~JJ
a4
1~
FIGURE 5-4
-
II
COMPRESSIBILITY AND COEFFICIENT OF CONSOLIDATION: ORINOCO CLAY
0.6
0.5
-
BORING
EXCELL.GOOD
FAIRPOOR
El
0
a
Ft
0
O3 0.4
0
NISHIDA (1956)
z
0*
vi
0.3
uw
w
0
0
20.2
0
20
40
60
80
100
NATURAL WATER CONTENT,
FIGURE 5-5
wN
120
140
(%)
EMPIRICAL CORRELATIONS WITH NATURAL WATER CONTENT:
ORINOCO CLAY
160
76
DM-7 (1971)
E
0
0
'O
80
00
U:
z
00
-J
0
2
0uD
O
50
0
w
c-
60
80
70
BORING
EXCELL.GOOD
FAIR POOR
El
0
a
F
0
0
0
90
100
110
TERZAGHI
AND PECK (1967)
90
too
120
a.
0.8
0
0.6
D.4
50
60
70
80
I10
LIQUID LIMIT, WL ()
FIGURE 5-6
EMPIRICAL CORRELATIONS
ORINOCO CLAY
WITH LIQUID
LIMIT:
120
77
6. NORMALIZED SOIL PROPERTIES AND SHANSEP STRENGTH PROFILES
Stress history results showed that both borings El and
F1 have an identical and well defined maximum past pressure
profile (Fig. 5-3).
Because the Orinoco Clay is normally
consolidated at boring El (OCR = 1.0) and only very slightly
overconsolidated at boring Fl
(OCR = 1.15),.the CK0 U Direct
Simple Shear testing program first concentrated on obtaining
properties
(NSP)
for
normally
consolidated
the normalized
soil
Orinoco Clay.
Overconsolidated CK0U Direct Simple Shear
results will be presented next, followed by a brief discussion
of how anisotropy effects undrained strength, and then this
chapter will be concluded by comparing the SHANSEP su profile
and TV, LV, and UUC data.
6-1 NSP FROM NORMALLY CONSOLIDATED CKIUDSS TESTS
0
The Direct Simple Shear apparatus was built by Geonor
and a description of the device was published by Bjerrum
and Landva
(1966).
The test procedures used for all CKIUDSS
tests are the same as those presented in Appendix B of Ladd
and Edgers
(1972), but using cylindrical Orinoco Clay
specimens having an area of 35 cm2 and a height of about
2.5 centimeters.
A CK 0 UDSS test has two parts: consolidation and shearing.
(1)
In the consolidation portion,
the clay specimens
were one-dimensionally (K0) consolidated beyond the in situ
78
maximum past pressure and into the normally consolidated
region in accordance with the SHANSEP technique.
To assess
the quality of a clay specimen, a compression curve can be
drawn to determine the vertical strain (e ) during recompression to -a
vo and the maximum past pressure by Casagrande's
method.
These "disturbance indices"
(Fig. 6-1) will be
compared with oedometer disturbance indices
(Fig. 5-2).
(2) The shearing portion consists of shearing the clay
specimen along a horizontal plane at a strain rate of about
4% of the specimen height per hour while varying the effective
stress
(av ) to maintain a constant height and hence constant
volume.
The failure plane is assumed to be horizontal and
the maximum value of the applied horizontal shear stress
(Thmax) is equal to the undrained shear strength.
Nine normally consolidated CK UDSS tests were performed,
three upon boring El specimens and six from boring Fl.
By
using the radiographs, the very best quality Orinoco Clay
specimens were selected for these CKQUDSS strength tests
and all TV(DSS/boat) ratios are equal to or greater than
1.0
(Fig. 6-1).
For some CK UDSS tests, a
was only
slightly greater than the in situ FvM, which made it
difficult to determine the virgin compression curve and
hence am by Casagrande's method.
Figures 6-2, 6-3, and 6-4 present data from the
shearing portion of the normally consolidated CKQUDSS
strength tests, which are discussed in the following
79
subsections.
a) Normalized Stress Paths
The stress paths in Figure. 6-2 are plots of the stresses
(Thand
v) on the horizontal plane normalized by dividing
them by the preshear a.
equals
At the start of shearing, a
vc and Th equals zero and thus all normalized stress
paths start at
Ev
vc = 1.0 and Th
Vc = 0.0.
As the hori-
zontal shearing force is applied to the clay specimen,
deformation occurs, av decreases until Thmax is reached,
and then both Th and Ev decrease due to strain softening.
The normalized stress paths fall into two groups,
those for clay specimens above (open symbols: &,0,
and below z = 70 ft
(closed symbols: A,E , etc.).
etc.)
Notice
that for specimens below z = 70 ft, there is a lower
normalized undrained shear strength (s /1
=
0.20) and
a lower friction angle at maximum obliquity (T = 200).
b) Normalized Stress-strain Curves
As illustrated in Figure 6-3, the normalized stressstrain curves fall into two groups, above and below z =
70 ft.
As stated in Chapter 2, normalized behavior means
that laboratory strength tests on clay specimens having
the same overconsolidation ratio will have similar normalized stress-strain curves and identical values of s /avc
independent of the magnitude of E
vc and
vm.
v
CK UDSS
80
Test Nos. 2 and 3 from boring El at z = 56 ft have the
same in situ maximum past pressure but Test No. 2 has a
preshear i
vC
=
2.26 kg/cm2 while Test No. 3 has a preshear
2
avc = 4.57 kg/cm , yet these tests have identical normalized
stress-strain curves.
Similarly, CK0 UDSS Test Nos. 10, 8,
and 9 were performed on clay specimens below z = 70 ft at
boring F1 having different in situ maximum past pressure
and preshear -vc values but identical normalized stressstrain curves.
Although there is some scatter (e.g.
compare Test Nos. 12 and 6),
generally at both borings
above and below z = 70 ft there are unique normally consolidated normalized stress-strain curves irrespective
of the in situ maximum past pressure and Evc and therefore
the Orinoco Clay exhibits normalized behavior.
The normalized stress-strain curves indicate that all
CK 0 UDSS tests have a large strain (yf = 11 + 4%) before
reaching the undrained shear strength.
Beyond Thmax,
most stress-strain curves remain relatively horizontal up
to about 18% strain.
c) Secant Moduli Data
Figure 6-4 presents a plot of secant values of E u/s u
versus the applied shear stress level Th/s u
The normal-
ized moduli are slightly higher for those DSS tests run
on specimens above z = 70 ft.
The Orinoco Clay
(P.I. =
35 to 55%) moduli data plot between Boston Blue Clay and
81
EABPL clay results.
The data presented in Figures 6-2, 6-3, and 6-4 are
summarized in Table 6-1 and in the table below:
Normalized Soil Properties From CK UDSS Tests on N.C.
Orinoco Clay 0
Boring El
z<70 ft
su a
rn.o.
E
so
/S
u
Boring Fl
z>70 ft
z<70 ft
z>70 ft
0.23
0.19
0.24
0.20
260
200
260
200
340
215
290 + 20
-
270 + 40
-
As discussed in Chapter 5, the compressibility and
swelling ratio increase below z = 70 ft.
The reason for
the difference in consolidation properties is an increase
in the amount of swelling minerals below z = 70 ft, which
is probably also the reason for the reduction in both i
at maximum obliquity and su
vc
Figure 6-5 presents a comparison of su/vc
from CK 0 UDSS
tests upon normally consolidated Orinoco Clay and other CL
and CH clays [Ladd and Edgers
(1972) and Ladd et al.,
(1977)].
The Orinoco Clay data above z = 70 ft fit in well with
published test results but the data below z = 70 ft are
lower than other CH clays.
As mentioned, the considerable
increase in swelling minerals below z = 70 ft is probably
part of the reason for this unusual behavior.
82
6-2
OVERCONSOLIDATED CK0UDSS TEST DATA
To obtain overconsolidated CK UDSS strength data,
0
Orinoco Clay specimens were K
consolidated in a Direct
Simple Shear apparatus into the normally consolidated
region, then unloaded (allowed to swell) and then sheared
to obtain the normalized undrained shear strength at varying
overconsolidation ratios such as OCR = 2, 4, and 8.
Six
CK 0 UDSS tests were performed on Orinoco Clay specimens, all
at depths greater than z = 70 ft.
The results are summarized
in Table 6-2.
Normalized undrained shear strength (s / vc) versus
overconsolidation ratio
(OCR) data from the six CK0UDSS
tests are presented in Figure 6-6.
Several important
conclusions are evident from this figure:
(1) For the Orinoco Clay below z = 70 ft, the s /a
u vc
versus OCR relationship plots very close to that of Boston
Blue Clay.
(2) CK0 UDSS Test No. 5 was performed upon a very
disturbed Orinoco Clay specimen resulting in a high value
of s /7vc
(0.383).
Therefore, consolidating highly disturbed
Orinoco Clay specimens well into the normally consolidated
region does not necessarily restore the in situ soil
structure.
(3) CK 0 UDSS Test No. 7 was consolidated to Evo rather
than using the SEANSEP consolidation technique.
The higher
su/c vc value (0.276) was probably caused by the decrease in
83
water content during recompression to avo'
The Orinoco Clay sU
VC
versus OCR relationship plotted
in Figure 6-6 can be expressed mathematically as:
su
vc =
(0.20) (OCR) 0.72
(Orinoco Clay, z>70 ft) .... 1
No overconsolidated CK 0 UDSS test were performed upon
specimens above z = 70 ft, but it has been stated (Atkinson
and Bransby, 1978) that equation 1 can be approximated
without performing overconsolidated tests.
Knowing s
_______U/
vc
for normally consolidated clay and the consolidation
parameters CR and SR, then:
su/ vc
=
(su1/avc for N.C. clay) (OCR) (1
-
SR/CR)
*..2
Above z = 70 ft at boring Fl, s /Uv
u c = 0.24 for
normally consolidated clay, SR = 0.04, and CR = 0.22.
Substituting these values into equation 2, the relationship
is:
su/ivc =
(0.24) (OCR)0.8 2
(for Orinoco Clay at boring
Fl, z<70 ft)
Normally consolidated and overconsolidated CK 0 UDSS
laboratory data are presented in Appendix B.
6-3
ANISOTROPY
This section is presented to illustrate the effects
of anisotropy upon F1S57 clay specimens.
Table 6-3
3
3
84
summarizes the results of one CK0 UE and three CK0 UC tests.
The stress paths, stress strain curves and other laboratory
data are presented in Appendix C.
Test Nos. TEl, TC4, and CK0 UDSS No. 9 were all performed
upon excellent quality normally consolidated F1S57 clay
specimens and sheared at about the same strain rate.
Since
these tests do not suffer from sample disturbance nor strain
rate differences, we can observe the effects of anisotropy
by comparing these three tests.
Anisotropy Effects
**
*
Test
Test No.
00
TC4
CK0 UC
CK UDSS
CKOUE
s/U
No. 9
30-600
TEl
9o0
CY
f
E 5 0 /s U
M.O.
0.23
3.4
390
270
0.20
12.5
225
200
0.16
9+
130
270?
As shown by the above table, the Orinoco Clay exhibits
a stress-strain-strength behavior that depends on the
applied stress system and the rotation of principal stresses.
The strength from the CKQUC test is an upper bound strength
*
6= angle between the major principal stress direction
at failure and the vertical direction.
su= 0.05(at-t-a3)Cs
for DSS :te-zts.
for triaxial tests and s
= Thmax
85
due to the vertical loading with no rotation of principal
stresses.
The strength from the CK 0 UE test
is- a iowor bound
strength due to anisotropy and increased pore pressures
caused by a 90 degree rotation of principal stresses with
a2 = a3 at the start of shearing and a1
of shearing.
a2 at the end
The CK0 UDSS test has an su/E1,c value that is
the average of the CKIUC and CK UE results and this "average"
strength is deemed most appropiate for bearing capacity and
stability analyses. --
6-4
SHANSEP STRENGTH PROFILES
a) Boring El
Fugro TV, LV, and UUC strength data (from Fig. 3-1);
TV data recorded in the M.I.T. geotechnical laboratory;
and the SHANSEP undrained shear strength profile are
presented in Figure 6-7.
The SHANSEP s
profile was
obtained from the following data:
(1) Stress History:
As shown in Figure 5-3, the in situ vertical effective
stress is about equal to the maximum past pressure determined from oedometer tests.
The Orinoco Clay at boring El
is normally consolidated (OCR = 1.0).
(2) Normalized Undrained Shear Strength:
From laboratory CK0 UDSS strength tests upon normally
consolidated specimens:
86
From 0 to 60 feet,
s /
= 0.23
From 80 to 140 feet,
s
= 0.19
0/vc
As previously discussed, the engineering properties
do not have an abrupt change at z = 70 ft and a transition
zone in engineering properties probably exists between
z = 60 to 80 ft.
A linear transition in the SHANSEP
strength profile was used between z = 60 to 80 ft.
The
table below (similar to Fig. 2-1c) presents some repres-
2
entative calculations (stresses in kg/cm ):
SHANSEP DSS Strength Profile (Boring El)
Depth (ft)
avoo
20
0.40
60
OCR
su
UFvc
ujv
s
0.40
1.0
0.23
0.09
1.22
1.25
1.0
0.23
0.28
80
1.67
1.69
1.0
0.19
0.32
140
2.97
3.02
1.0
0.19
0.56
u
In Figure 6-7 above z = 60 ft, most undrained shear
strength data from TV, LV, and UUC tests are less than
the SHANSEP strength profile because the sampling tubes
were hammered, resulting in increased sample disturbance
and lower values of su.
Below z = 60 ft, almost all the
LV and UUC data are greater than the SHANSEP strength
profile.
This is because the sampling tubes were pushed
into the soil strata using Fugro's "WIP" sampling
87
equipment resulting in much less sample disturbance with
higher LV and UUC data due to strain rate effects and
anisotropy.
b) Boring Fl
In Figure 6-8, two SHANSEP undrained shear strength
profiles are presented.
The lower SHANSEP profile was
obtained from the following data:
(1) Stress History:
The Orinoco Clay at boring Fl was assumed to be
normally consolidated (OCR = 1.0).
(2) Normalized Undrained Shear Strength:
From laboratory CK UDSS strength tests upon normally
consolidated specimens:
From 0 to 60 feet,
s /_c=
t~vc
From 80 to 140 feet, s /
0.24
c = 0.20
with a linear transition between z = 60 to 80 feet.
table below presents some representative calculations
(stresses in kg/cm 2
Lower Bound SHANSEP Strength Profile (Boring Fl)
Depth (ft)
avo
OCR
20
0.34
1.0
0.24
0.08
60
1.09
1.0
0.24
0.26
80
1.47
1.0
0.20
0.29
140
2.63
1.0
0.20
0.53
su
vc
su
The
88
The upper SHANSEP strength profile (Fig. 6-8) corresponds to an OCR = 1.15.
This su profile was computed by
substituting OCR = 1.15 into equations 1 and 3 to obtain
s /3
=
0.27 for Orinoco Clay above z = 60 ft and su/vc
0.22 for Orinoco Clay below z = 80 ft.
However, since the
reason for the slight overconsolidation (OCR = 1.15) at
boring Fl is unknown, the author recommends using the
lower SHANSEP strength profile for stability and bearing
capacity analyses.
From z = 20 to 40 ft (hammered samplers), most TV, LV,
and UUC data are below the SHANSEP strength profiles.
Even
though below z = 40 ft better quality specimens were obtained
because of pushed samplers, about half of the LV and UUC
results plot below the SHANSEP strength profiles, probably
because these tests were performed on more disturbed
specimens resulting in lower su values.
c) Comparision Between SHANSEP Strength Profiles at Borings
El and Fl
Comparing the SHANSEP profiles at borings El and Fl,
the SHANSEP profile in Figure 6-7 plots midway between the
two SHANSEP profiles in Figure 6-8.
Hence, borings El and
Fl have very similar undrained shear strength profiles.
But by comparing only TV, LV, and UUC data (e.g. compare
Fig. 3-1 and 3-2) this important conclusion is not so evident
due to the very large scatter in the results of these
89
conventional strength tests.
Thus, because the SHANSEP
method has considered the effects due to sample disturbance,
strain rate differences and anisotropy, more reliable su
profiles were obtained by this procedure, which also
indicated that both borings El and Fl have an almost
identical undrained shear strength versus depth.
TABLE 6-1
All stresses in kg/cm
2
-
z(ft)Zf
Test
UP
WN(%)
No.
(Boring) oample) PI(Z)
SUMMARY OF CK UDSS TEST DATA: N.C. ORINOCO CLAY
Eat.
vo
c
at0
vo
At Maximum Th
-
vc
te(day)
Y
aa)
_(1)
Est. U
£ at
v
T
0
h
a
v
At Maximum Obliquity
o
17T
E50
_1
h
00
Remarks
Y
aU
M
(L
(9)
46.6
0.4
13.2
0.99
10.9
0.238
0.576
22.5
275
27
0.170
27.7
36.8
(Fl)
6
(S12)
61.0
43.7
0.64
0.74
3.1
15.2
2.02
0.91
15.2
0.243 0.599
22.1
270
27.5
0.193
25.0
55.8
2
45.0
1.13
11.6
0.226 0.576
21.4
340
30
0.173
26.9
(E)
(sS5)
33 0
1.16
1.7
1.7
11.6
0.229
(El)
0S15)
21.1
33.0
340
1.16
32
21.2
0.98
0.165 26.2
142
029059
11
30
32
0152.
18)
45.9
1.2
9.3
.86
7.3
0.240
0.635
20.7
310
23
0.114 24.7
(F)
(s1)
9
1.74
125.0
2.86
10.7
0.204
0.603
18.7
260
25.7
0.110
21.3
1GO.5
VEY
96.5
(Fl)
8
(S24)
61.0
48.9
1.79
2.06
6.0
15.7
4.98
1.66
8.1
0.200 0.666
16.7
310
22
0.145
19.3
2nd shear
of No. 7
128.1
9
65.6
2.40
5.2
2.86
12.5
(Fl)
(S57)
0.204
57.1
2.78
8.2
0.607
1.07
18.6
225
27
0.098
20.1
EXCELLENT
14
.13
51.8
2.84
8.0
13
(El)
(S27)
39.4
0.193
2.90
14.7
0.605
17.7
215
25
0.098
18.7
GOOD
67.6
(1) from dashed line in Fig. 5-3
(2)
estimated from CK UDSS test
0.99
0.593
FAI I
. (
)
EXCELLENT
Z.0.82)
E
(2 )
D
)
0
GD 3)(2)
FAIR
(2)
TABLE 6r-2
All
stresses In
SUMMARY
OF CK UDSS TEST DATA;
At Maximum
wN(%)
z(ft)
(Boring)
(Sample)
PI(%)
96.5
7
61.0
£vo
y at
Est.
vo
Est.
(S24)
48.9
2.40
98.8
5
60.2
2.07
(1)
2.11(2)
E50
lh
h
VC
v
vm
c£
v
at 5
(OCR)
vc
6.0
(%)
a
vc
5.3
0.276
0.709
470
0.383
1.018
280
s
vc
u
(%)
a
1.72
6.0
1.79
(F)
42.8
vm
At Maximum Obliquity
h
Th
-y
oo_5
(S21)
CLAY
kg/cm 2
Test
No.
(El)
0,C. ORTNOCO
2.40 (Est)
(1.4 Est)
16.3
Not Reached
2.02
2)12.0
4.00
21.4
28
0.23
1
._(1.98)
99.8
4
57.0
2.10
8.5
(S21)
32.0
2.13(2)
62.9
2.41
63.4
(2)
2.77(2
19.1
Recompression
to aIO
tC
0.84 days
Poor sample
.)3
(a
= 2.dy
=
__c
2.50
14.6
(El)
0.42
Remarks
0.337
0.986
180
21
0.32
0.36
Fair sample
(5 z 2.0)(3)
5.00t
-
______(2.00)
128.3
(Fl)
16
(557)
9.3
16.4
2.29
11.0
0.328
190
1.073
19
0.31
0.32
4.55
(Fl)
17
(S57)
64.2
61.0
F7
.
2.42
2.78(2)
8.5
1.16
16.3
13.5
23
0.545
125
1.348
18
0.54
0.41
(Fl)
18
(Fl(57)
(S57)
62.9
545
54.5
2.42
278(2)
2.78
6.7
9.
9.4
(1) Based on test No. Oed-6
(2) From dashed line in Fig. 5-3
(3)
Estimated from CK UDSS test
Fair sample
1.9/3)
(avM
-
c
0.59
.3
4.53
(7.70)
days
0.1dy
Fair sample(3 )
::: 1.7)
(a
t = 3.0 days
4.9'1)t
(3.91)
129.1
0.31
t_=.da
(1.99)
128.9
2.1 days
15.2
0.875 1.829
80
17
0.86
0,49
days
Excellent saple
(a-vM -: 2.5)(3)
t
_
1.0
c == 1.0
1.0
t
days
H
TABLE 6-3
All stresses in kg/an
SUIVARY OF CK U TRIAXIAL TEST DATA: N.C. ORINOCO CLAY
2
At Maximum q
z
(ft)
Test
(Boring) (Sample)
99.1
TC3
w,(%)
Est. Gvo
E
PI(%)
Est. ; (1
inn
Evc
57.4
2.08
at
a0vo
at 5
vc
7.0
vc
K
C
q
( )
(S21)
39.0
2.11
14.6
vC
Eso
0vc
5
U
q
Remarks
aVC
(%)
3.52
4.8
(El)
At maximum Obliquity
0.269
0.621
25.7
410
13
0.257
27.1
Good Sample
Large Au at
start of shec
tc - 2.8 days
0.625
'.0
I,.j
99.5
TC2
51.5
2.09
6.0
3.48
6.2
(El)
(S21)
31.5
2.13
12.7
0.61
128.7
TEl
60.1
2.41
2.5
3.01
6.2
(Fl)
(S57)
57.1
2.77
4.1
0.60
129.3
TC4
61.8
2.43
3.7
2.90
(2)
2.6
(Fl)
(s57)
51.9
(1) From dashed line in Fig.
2.79
5-3
5.7
0.60
(2) Extent of reliable data
0.277
0.617
26.7
300
NOT REACHED
Good Sample
tc - 2.7 days
0.175
0.510
20.1
130
NOT REACHED
tC
NOT
0.260
0.715
21.3
390
Excellent sample
t - 1.7 days
ACCURATE.
FAILURE PLANE
DEVELOPED AT
c - 2 to 3%
=
2.2 days
ev (%) AT Mvo
TV (DSS)/(BOAT)
0.4 0.6 0.8
1.0
1.4
1.2
1.6
0
2
4
6
8
BORING
El
OCR a im /do
10
1214
0.4 0.6 0.8 1.0
~1~~ ~
1.2
1.4
1.6
-
FAIR-
EXCELL.-
GOOD
0
POOR
U
20
0
0
2,5
0
40
00
0
03
0
3-
Law.
80-
'.0
U)
-U-
0
0
300 --100
-
- -
-
-
-
0
--
-- -
120
- -
--
- -
--
-
0
140
--
FIGURE 6- I1
CK UDSS TEST DISTURBANCE INDICESs
ORINOCO CLAY
-
1(t) TEST
No.
27.5
36.8
55.8
56.0
67.6'
82.0
96.5
128.0
SYM. BORING
12
6
2
3
a
0
0
I
v
10
A
8
a
*
0
9
13
134.0
0
ww
Pi
(%)
(%)
62.5 46.6
61.0 43.7
45.0 33.0
47.0 33.0
59.4 47.9
59.2 43.9
61.0 48.9
65.6 57.1
51.8 39.4
Fl
Fl
El
El
F1
Fl
FI
FI
El_
1
n 4
I
I
0.9
1.0
26'
0.3
Th
oVcO. 2
0.1
ENVELOPES AT MAXIMUM OBLIQUITY
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
rv / fvc
FIGURE 6-
2
NORMALIZED STRESS PATHS FROM CK UDSS TESTS: h.C. ORINOCO CLAY
0.3C 0.30
0. 5
-rn
.0--
R5 -Jjpv-
1
I
-a--
0a-~o--
ZIrZIIF~~I
Th
ov c
0.
ti'.0
z (ft)
TEST
BORING
SYM.
-
0.0 5
-
0
a
4
WN
P1
4%) 4%)
No.
0.10
w
injinp
mm,
t
k I--
i
0.2 0
r
u-V
-
27.5
12
A
Fl
62.5 46.6
36.8
6
0
Fl
61.0 43.7
55.8
2
El
45.0 330
560
676
3
I
0
0
V
El
Fl
470 33.0
594 47.9
820
10
A
Fl
59.2 439
6.
128.0
8
9
0
Fl
Fl
6[0 48.9
65.6 57.1
134.0
13
6
I
5.8
1E
8
39.4-
10
SHEAR STRAIN,
FIGURE 6-3
-
12
14
16
Is
20
y (%)
NORMALIZED STRESS VERSUS STRAIN FROft CK UDSS TESTS: N.C. ORINOCO CLAY
96
z (ft) TEST
SYM. BORING
No.
1000
27.5
36.8
55.8
12
6
2
a
3
F1
o
56.0
67.6
82.0
96.5
3
0
11
7
A
I
El
El
Fl
Fl
F1
10
128.0
8
9
134.0
13
800
Fl
Fl
El
w "
P,
(%)
(%)
62.5
61.0
45.0
46.6
43.7
33.0
47.0
59.4
59.2
61.0
33.0
47.9
43.9
48.9
65.6
51.8
57.1
39.4
N
17
_________
afnL-
I
4
It
II
7
400
0
BC (PI=21 %)
200
100
IF____SP 1
0
____
so
0
0.2
____
0.6
0.4
0.8
Lo
Th/su
FIGURE 6- 4
NORMALIZED UNDRAINED MODULUS FOR CKUDSS TESTS:.
N.C. ORINOCO CLAY *
0.35
1
0.30
w
0
C)
0.25
0
lb
N1
00
0
I.
0.20
-
-
FROM LADD 8 EDGERS (1972)
AND LADD ET AL. (1977)
-0
0.15
_-
i < 7d ORINOCO
x z>70
0.101
..
0
J CLAY
1_
_
20
40
1
60
80
PLASTICITY INDEX, PI (%)
FIGURE 6-5.
Fu /v-
I
VERSUS PI FOR NORMALLY CONSOLIDATED CL AND CH CLAYS
1__._.
100
98
1.61
Me. ORGANIC
(P1=34%)
1.4
EABPL
(P1=75 %10)
,1
12
ORINOCO CLAY
DEPTH
N.C.
z<70'
O.C.
-
-
o
BBC
(PIZ21 %)
z >70'
0
I,
W.
/
ORINOCO
CLAY
'I,
/
0
0.'
0
(0.200) (OCR) .7 2
(2 TESTS)
RECOMPRESSION TO
W.
y
I-
I
2
4
OCR a rm/rc
FQURE 6-6
EFFECT OF OCR ON
Su /vc
6
8
UNDRAINED SHEAR STRENGTH, su (TSF, kg/cmt)
X
LEGEND
FUGRO: LAB VANE
20
------
-
-
-_
--
0
40
-
--
-
-_--
-
-
-
-
-_
- -_--
-
-
FROM tvm PROFILE (OCRaI.0)
a
X
- -WIP
SAMPLES
I
III
in 80
+
0
--
++
- - --X)
++
00
+
6
D0
x
--
100
120
-
x
+
----
x
0
x
0
-
+
x
141
FIGURE 6 - 7
COMPARISON OF UNDRAINED STRENGTH DATA: BORING El
0
*
TORVANE
X
SUUc
0
MIT: TORVANE
+
SHANSEP DSS
4x
60
1.0
0.9
0.6
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
UNDRAINED SHEAR STRENGTH, Su (TSF, kg/cma)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-
0.8
1
09
-
LEGEND
FUGRO: LAB VANE
20
-
Xix
40
T
+
+
meA_
p
SAMPLES
X
UuC
0
MIT: TORVANE
+
SHANSEP DSS
+
+ +
60
c0\
4f1+
X-
0
TORVANE
X
X
1-
+ (0: +
C0
FROM
H
03
03
im PROFILE (OCR 1. 15)
so
MINIMUM FOR N.C. CLAY (OCRaI)
X
100 --
0
4
-
+
x+
X0
+. +
+
X
140LFIGURE 6-8
COMPARISON OF UNDRAINED STRENGTH DATA: BORING Fl
0
101
7.
SUMMARY AND CONCLUSIONS
The Orinoco Clay is a thick deposit
(30-40m) of soft,
highly plastic CH-OH soil encountered throughout vast areas
of the Gulf of Paria and the Orinoco Delta.
Undisturbed
tube samples of Orinoco Clay obtained from borings El
Paria) and Fl
(Gulf of
(Orinoco Delta) were utilized for laboratory
soil tests in order to determine their engineering properties,
and a major objective of this thesis has been to present
the results of those tests.
The engineering properties of
the Orinoco Clay are needed for the design of oil platforms
to be built in offshore Venezuela.
(a)
Results of Classification Tests and Composition
Analyses
The Orinoco Clay at boring El is classified as
a CH Clay and has a P.I. between 25 to 45%, whereas the clay
at boring Fl is classified as a CH to CH-OH clay with a P.I.
between 40 to 65%.
Table 7-1 summarizes the plasticity
index and natural water content data.
Mineralogy results indicate that the Orinoco Clay at
borings El and Fl has the same basic composition, the principal clay minerals being kaolinite, illite, and swelling
minerals (smectite).
The rest of the soil consists of
quartz, mica, and weathered feldspar grains with small
amounts of carbonates and organic matter
(about 2%).
102
b)
Radiography
Sampling tubes containing Orinoco Clay were
radiographed and the radiograph prints
detected the pres-
ence of gas pockets, cracks, zones of disturbed soil, and
different soil structures.
The radiograph prints clearly
indicated the proportion of "good-excellent" quality clay
to that of disturbed soil.
Thus radiography was an
invaluable tool used to locate the best quality Orinoco
Clay specimens before extruding the soil for sophisticated
laboratory tests such as oedometer and CK UDSS tests.
c)
Stress History and Consolidation Properties
The results of seventeen oedometer tests showed
that borings El and Fl both had an identical and well
defined maximum past pressure.
But due to different natural
water contents, the computed in situ vertical effective
stress assuming hydrostatic pore pressures and 100% saturation
is less at boring Fl.
At boring El, the in situ vertical
effective stress is about equal to the maximum past pressure
and thus the Orinoco Clay at this location is normally
consolidated (OCR = 1.0).
At boring Fl, the deposit is
slightly overconsolidated, OCR = 1.15 (see Fig. 5-3),
perhaps caused by wave action,
The consolidation properties (i.e. CR, SR, c ) are
very similar at both borings, but with different values
above and below z = 70 ft.
Below z = 70 ft, the Orinoco
Clay is more compressible, probably caused by a significant
103
increase in content of swelling minerals.
d)
SHANSEP Stress-Strain-Strength Parameters
The SHANSEP strength testing program concentrated
on obtaining normalized stress-strain-strength properties
from CK UDSS tests because this type of test yields an
"average" strength (due to anisotropy) which is deemed
most appropriate for stability and bearing capacity analyses.
At both borings El and Fl, the DSS tests yielded similar
normalized soil properties
(see Table 7-1)
but once again
with different values above and below z = 70 ft.
This
different behavior is probably also caused by the increase
in content of swelling minerals below z = 70 ft.
e)
Comparision of "Conventional" and SHANSEP
Undrained Strength Profiles
Figures 6-7 and 6-8 compare su data at borings El
and Fl obtained by "conventional" practice and the SHANSEP
method.
The former includes results from Lab Vane, Torvane,
and UUC tests, and these tests yielded wide scatter due to
sample disturbance, strain rate differences, and anisotropy
effects.
Above z = 60 feet at boring El, the sampling tubes
were hammered, causing increased sample disturbance and
hence a majority of the TV, LV, and UUC strengths were
less than the SHANSEP strength profile (Fig. 6-7).
Below
z = 60 ft in Fig. 6-7, almost all of the LV and UUC data
show higher su values.
These higher strengths from "pushed"
104
samples probably result from a combination of: better
sample quality; the fast strain rate; and consideration of
anisotropy (pecular mode of failure in LV tests and vertical
loading with no rotation of principal stresses in UUC tests).
From z = 20 to 40 ft
(hammered samples) at boring
Fl, most TV, LV, and UUC data are below the SHANSEP strength
profiles (Fig. 6-8).
At depths greater than z = 40 ft,
about half of the LV and UUC data plot below the SHANSEP
strength profiles, probably because these tests were performed
on more disturbed specimens resulting in lower s
values
even though better quality specimens were obtained because
of pushed samplers.
Comparing the SHANSEP strengths at borings El and Fl,
the s
profile in Fig. 6-7 plots midway between the two
SHANSEP lines in Fig, 6-8.
This is because of the identical
maximum past pressure at both borings and similar normalized
undrained shear strengths from strength tests.
But, comparing
only "conventional" TV, LV, and UUC data (e.g. compare Figs.
3-1 and 3-2) this important conclusion is not so evident
due to the very large scatter in the results.
Because of the similar SHANSEP strength profiles at
both borings El and Fl, they could be used at other sites.
Suppose a decision is made to construct an oil platform
between borings El and Fl.
Geophysical survey data reveal
that the Orinoco Clay is continuous between borings El and
Fl and if an in situ test, e.g. a piezometer probe, gives
105
approximately the same results at borings El, F; and
new site, then the SHANSEP strength profile in Fig. 6-7
(which is the average of the two profiles in Fig. 6-8) can
be used at the new site for preliminary oil platform designs.
106
TABLE 7-1
ENGINEERING PROPERTIES OF THE ORINOCO
CLAY
Boring Fl
Boring El
z < 70 ft
i
z > 70 ft
z < 70 ft
z > 70 ft
INDEX PROPERTIES
Natural
water
content
75-45%
53%
90-63%
Plasticity
30-38%
38-45%
40-50%
65%
1
50-65%
IndexI
STRESS HISTORY AND CONSOLIDATION PROPERTIES
OCR
Normally Consolidated
OCR = 1.0
Slightly Overconsolidated
OCR = 1.15
CR
0.19
0.30
0.22
0.33 ± 0.01
SR
0.03
0.05
0.04
0.08
N.C. c
C.v
cm2/sec
-4
7 x 10~
-4
2 x 10~
5 x 10
NORMALIZED SOIL PROPERTIES (N.C.
-4
-4
2 x 10
CK 0UDSS TESTS)
0.23
0.19
0.24
0.20
~ at M.O.
260
200
260
200
E
340
215
s /9
u
vc
/s
290 ± 20
1270 ± 40
SHANSEP STRENGTH PROFILES (FIGS. 6-7, 6-8)
z < 60 ft
-s**
s /a
U
vc
*
**
0.23
z > 80 ft
I0.19
z
0.27
Linear transition for strength profiles
Upper bound strength profile
< 60
in Figure
i
z
> 80 ft
0.22
**
between z = 60 to 80 ft.
6- 8 for OCR = 1.15.
107
REFERENCES
Note:
ASCE = American Society of Civil Engineers
ASTM = American Society for Testing and Materials
JGED = Journal of Geotechnical Engineering
Division
JSMFD = Journal of Soil Mechanics and Foundation
Division
ICSMFE = International Conference on Soil Mechanics
and Foundation Engineering
Allen, L.R.; Yen, B.C.; and McNeill, R.L. (1978), "Stereoscopic X-Ray Assessment of Offshore Soil Samples",
Offshore Technology Conference, Vol. 3, pp. 13911399.
Atkinson, J.H. and Bransby, P.L., The Mechanics of Soils,
McGraw-Hill, London, 1978, pp. 329-336.
Bjerrum, L. and Landva, A. (1966), "Direct Simple Shear
Tests on Norwegian Quick Clay", Geotechnique, Vol. 16,
No. 1, pp. 1-20.
Butenko, J. and Hedberg, J, (1980), "The Distribution of
the Orinoco Soft Clay", Report by INTEVEP in Venezuela,
July, 161 p.
Casagrande, A. (1936), "The Determination of the Preconsolidation Load and Its Practical Significance", Proc.
lst Int. Conf. Soil Mech. and Found. Eng., Cambridge,
Mass., p. 60-64.
DM-7
(1971), Design Manual - Soil Mechanics, Foundations, and
Earth Structures, U.S. Naval Facilities Engineering
Command Publication, Washington, D.C.
Fugro Gulf, Inc. (1979) "Geotechnical Investigation Golfo
De Paria, Offshore Venezuela", Report to INTEVEP in
Venezuela, Report No. 79-005-5, December, 82 p.
Ladd, C.C.
(1971),
"Strength Parameters and Stress-Strain
Behavior of Saturated Clays", M.I.T. Research Report
R71-23.
108
Ladd, C.C. (1973), "Settlement Analysis for Cohesive Soils",
M.I.T. Research Report R71-2, No. 272, 115 p. (revised
1973).
Ladd, C.C.; Azzouz, A.S.; Martin, R.T.; Day, R.W.; and
Malek, A.M. (1980), "Evaluation of Compositional and
Engineering Properties of Offshore Venezuelan Soils,
Vol. 1", M.I.T. Research Report R80-14, No. 665, 286 p.
Ladd, C.C. and Edgers, L. (1972), "Consolidated-Undrained
Direct-Simple Shear Tests on Saturated Clays", M.I.T.
Research Report R72-82, No. 284, 354 p.
Ladd, C.C. and Foott, R. (1974), "New Design Procedure for
Stability of Soft Clays", JGED, ASCE, Vol. 100, No.
GT7, pp. 763-786.
Ladd, C.C.; Foott, R.; Ishihara, K.; Schlosser, F.; and
Poulos, H.G. (1977), "Stress-Deformation and Strength
Characteristics", Proc. 9th ICSMFE, Tokyo, Vol. 2,
pp. 421-494.
Ladd, C.C. and Lambe, T.W. (1963), "The Strength of 'Undisturbed'Clay Determined from Undrained Tests", ASTM,
STP 361, pp. 342-371.
Lambe, T.W. (1951), Soil Testing for Engineers, John Wiley
and Sons, New York.
Lambe, T.W. and Whitman, R.V. (1969), Soil Mechanics, John
Wiley and Sons, New York.
Madsen, O.S. (1978), "Wave-Induced Pore Pressures and Effective Stresses in a Porous Bed", Geotechnique, Vol. 28,
No. 4, pp. 377-393,
Nishida, Y. (1956), "A Brief Note on Compression Index of
Soil", JSMFD, ASCE, Vol. 82, No. SM3, pp. 1207-1 1207-14.
Terzaghi, K. and Peck, R.B. (1967), Soil Mechanics in
Engineering Practice, John Wiley and Sons, 2nd ed.,
New York, 729 p.
Wilun, Z.and Starzewski, K. (1972), Soil Mechanics in
Foundation Engineering, Vol. 1, John Wiley and Sons,
New York, pp. 187-190.
109
APPENDIX A
CONSOLIDATION TESTS
This appendix presents typical laboratory data from
oedometer tests performed on Orinoco'Clay specimens.
Six
representative consolidation test data and compression
curves
(Figs. A-i to A-6) were chosen to further
illustrate the effects of sample disturbance.
SAMPLE
TEST NO.
COMPRESSION CURVE
QUALITY
FlS30
16
Fig.
A-i
Excellent
FlS30
7
Fig.
A-2
Poor
F1S57
18
Fig.
A-3
Excellent
FlS57
12
Fig.
A-4
Poor
ElS27
14
Fig.
A-5
Good
ElS18
2
Fig.
A-6
Poor
Additional laboratory data from oedometer tests is
presented in Appendix B of Ladd et al.
(1980).
CONSOLIDATION
Project
Type of Test srAA4b4i
Location
Fl S*s
/rATvCEF
Soil Type
ORI__oCO
C.L.AV
Initial w(%) 65--o
Gs
Void Ratio e
S/6(%)
/,7
2.72.
/o/
_t(
h r Ev(%)
/ WP(%)YO. .P. 1.(%
0,/0
o.-o
z.oZ,5
1.00
O.4/
-3o
2.
.15,0
2.00
.
.co.9
/.7,v7
o 2.oo
1'3 . ?q7
/.'/'4
/.-1/
/.9ZZ~
/LL3L
1.33
zo.k913
1,1741
2.0
0-7
/3.3 0 8
/'
O.53
2.00
O.47
0.5~0
2.5"0
a.5'
e
/6.7
7
22.KI
20./0
15-. C;-
/.3/5~
/.1 1/
/-/9L/
1.317
No.oe&-/k Tested by x.ib.
Date Z A3j. I/,o
/.'tp
a
Sample Height
6..3,
Sample Diameter
WN(%)-.o WL(% ) 9,o Corrections APPA19ATv!
Primary
_vc
TEST
t(hr)
-
q.1
/2,.3
0LL...
)5
5-j/ Units: &vC
Total
Ev(%)
ec
/. ?/?
0. 000
/.7/7o
/.4
/.
72q
2.37
L/-./2.
21.r-C
/(.
zq.o
/z.9zs
/-312
/
/5.7?
/,3/3
23.o
z .SiZ..
V1.7
./
/9. S;77
15.4 0
.0/
2.20c
/- o_,?
'.2 3oAl
-. ( 9 33
q,.'lo0 /. 41s.
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M. I. T.
frogkt
I
-
______
c
Coef.of Consol.
C (%)
e
7/c
Jv
e_"om6 -ss
Cr
,Lpry
L 5ec
Remarks
_
C>
.8_~
O7 97-~SL
-
_
-- %_1?_
_
Remarks
F---Si4
WkrER
E.
v SASEb
Co
too
L6M to. -/lmc- cux0vf
CONSOLIDATION
Project
AITE VE P
Soil Type -- /
,Ao 0
CLA Y
Initial w/(%) 5-1.'
Void Ratio e /.C95
Type of Test srAb, 'A
Fps o
Location
Tested by A, w. 1.
Date An r/977
e-#..
S imple Height
Z.35
S 3mple Diameter - s-,
Gs 2'72 WN(%) -5. P WL(%) /0/.
Correc t ions A rf/T ATu-s COe/O/Z
/,(ry
4
S(%)9-5.
wp(%)7V'/o RI.(%)LL.g Units:
SVc
Ih/
cv <-22 s .e
Primary
t(hr)
VC
0.2 O)
Z
Ev(%)
,0
/.0 5
01370
0./ .52.
/10/
Total
t (hr)
e
0.10
2.t/T
6/.45,
J.
/
2.00
3,5T0
2.b
2.S
22.S
/_._00
/2.00
3.00
0./0
f.. C/:
2.4
.
L.~' S?
/.1.3. 1._
/q . 5.117
6,0784.i/
/1./0
/.29
5z.q2.
/4.-09
2129
1.1/24
Z/e9L
I?.iz.
2,,az.
22-/62
29.406
0.397
2.1q59 q o.8z
/9.?Y?.
70.q7
/9/o1
I.fJ!
2.4/a7
30.2V/
26.3i(
2 q-07,27o
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M. I. T.
e
/9, (195
2.2S
Coef. of Consol.
_cc((%)
o.'/z?
/5.20i
/./f3
."23
No. oel>- 7
o0o00o
0
/.
/.395
2, 5 /1.8 7
2.06'
-5.6o 6-
/4c
Ev(%)
/-5.6' 0
0.99
/.7s
2.So
TEST
Remarks
ogt
)
C
_____
_5
H
H
H
/.65_
/./?7 / 4___7
._34.o
2.z.
O.7
/-0'?
0.3526.9
o.7
0.9_
/. / ? F
35
-- 7
Remarks
3A6
Z
31
/
/.
-
y
z.I
10
__
____
E
Cu '
oAj
.
d
FoPA
Lo6- T/ME
CONSOLIDATION
Project
Soil Type
Type of Test :rAtbqb No. o0b- lo Tested by 8. LO.b.
F1 55-7
Location
Sample Height
Sample Diameter
Gs z.7z WN(%)6..bWL(%)
99.o Cor rections AeeAtA-rus
S(%) /00(. w p(0/%/-? P.RI.(%) 5-Un its: ovc kJ/
Cv
vcp
opwog o
/TrC
Ca-Al
Initial w(%)
(o-
Vold Ratio e /-71
Primary
t ( hr)
____c
._ O2__
0.0
O.g
2L
f-J
/.7'1/
00
Q
/o300
3,21'
.7/3
/./2
C
6.'G1.
IZ.00
0.80
3.oo
.57
o.50
2.
0 1.
2
.
/2-
8
2/.272
,
_
ev(/)
/.3f
7.27 .
c; 7
_
Total
o_oo
/.7
0.23
00
Ic_0:.9__
t (hr)
e
E(%)
_0.0
TEST
13.07
2..z 7
e
/.7Zg
V
/317
_
0_to
'.S
.
''.33
/f-. 5-0Z
,9$ /.9' 2?.Oo /o..1
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T.
__
e
e
CorE'cW55d,3 .Ty
cA/s.-c
ogt
Remarks
______
Hu
--
-- _2-_x
/.6S5
I. '1 _ _.. 0 0__|_.
1-.,3 zt /4,5~.39
/1,1*5 ~
6.2.5
I 10 1 /-29?. 1 .2-01)
) 7e.
ZG . - /2 5 1
e/.oT
.7-12
ol.4 .02.q /.235/.//1
/2.3q
23.7S
/./3-
/7./31
1.1_s
/- 4-
Coef. of Consol.
C.(%)
/-'/5?
/.799
Date
iKI
W/
-q
x
xt
/-337
/1 b
Remarks
Ev 645Eb
ON
(1 TU OF-b-Q2
FoM
-o-
-T/MA
CONSOLIDATION
Gs
6Y.8,
Void Ratio e /.767
0,0 / ----_ 0.co0
/.7?1
/.?4.
0.19
0? .91
0,10
0, 2-g 5
0.
5
/.17
/.33
/.0
t(hr)
0 3.0X2
/.?49
6.Zo
O./i9
/.
2.33
2.6
Z..Ie0
/-7o9
yr
cc/)
e
Ev(%)
_
_
_
__
g7-4. 6P
/I.q6
,q(s7
/3
9
g
1.6!-
-
2 -
qq-
7_
. x /0
/.?.-.-.2.
2. 93
1, qs.
?__56
20.g2-,
/19L
0.5
R_
3
Z.Z el
Z 3 . /9 6(
6. F3
.1
l ,1/7 z /2.7Y7
/6.02<
1q 2q.67
2 1
21.-2
/.0
6.73q
0.987
42-25
/./q3
06
3,
/q //0-1102~O-5
/2.~~~~2
/
3,oV"7 /.Yo(
21.00
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M. I. T.
/2.i7g
2
2.,
21 /o?/
/32.
-_6x
V4
0g,x.9
--.-3
15._
_.?
r
/0,- 1y I?
1o
/.5
R
logt
{.796
2.1/
./7
Cvc
.-
Coef. of Consol.
Total
e
ci--'
.
gWArOs (OAR55/C.1rY
Units:
wp(%).Y/.l PI.(%) 5-7.
S(%) 9?7Ev(%/)
A
wN(%)4/..d. wL(%) 11.o Correc tions
2.,?z
Primar
t(hr)
Z.o 00 e
Sc mple Diameter
Initial w(%)
fvC
Sample Height
Location
1r 7
Date
No. ocb-r.. Tested by R. w.b.
Type of Test sfAAIUWf
/'U TE vr P
Project
9 /A/oc.o
Soil Type
C tA
TEST
/.-
-o
1 |
.
'
l3 5
_
Remark s
Ev
B ASE b ON
C ()S kVrI
16
Fgbeim
Lo&- riE
CONSOLIDATION
Type of Test srAlTbA#>
Location
Et. s 2.7-
tF7vcP
/
Project
Soil Type Ogimo-o
TEST
No. oEt-
Tested by
Date
R- W. b
Sample Height
2.09 C'".
Sample Diameter
Initial w(%)
Corrections APPARATUS
WN(%) 53 WL(%) 7.72.3 wp(%)3.L./ PI.(%) 3T-/ Units: &vc kP /
cA
S(%)
Primar y_
t(hr) E(%)
Total
____
0./o
-
6.1s~
0.03
0.000
6.
3
e
o
2.P97
jf
/.?S
3.50
.
3-3
'
.7C.
.7
C.oO
2-33
/2.00
/ .61
.3.07
3.oo
/.oo
7-.0s
0.! o
0.10-
4.7-o
/5
/.S2/
1473
0.95'2.
/-0,3
1,.6 7 /.18
I 9-54'S
1,33)
.oOO
----
17.0
.
/ 9
0.0
.
0.764
z..
1.
/.'z?
/-.35/,
e(%)
t (hr)
/.~S77
/.57(.
o.6z.
1.00
-
Z.72.
.
Void Ratio e /-7?
dVC
4
1J
20.1
/'/.5
75.3
'/8,7
239.o
27. F
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I. T.
9.5j
/6.637
2q.03
zo.
y. 5b'e
2./o1
Coef. of Consol.
Vr
logt
______
e
C (%)
.
MPCSs B/Ty
C
rSIA
Remarks
/.577
/.5
/-5S7
/.025/.
i 9.,(
a~.
-39 -1
/.331
./s'
H
H
/I IS/?
*J
.95-
-
/ -I
3.3 X/O
3./
0,6
0. :'3 S-
/.O-/o
/.Zo3
J1IL.
Remarks
.-
x/0
2.3-x10
_
__
EV
A
e..oK vES.
oM
J100
FRoM
LoG' TIAi
CONSOLIDATION
Type of Test 6r-ANbArb
E I. I
Location
1"TE 'F P
Project
Soil Type 0 -4#Noco
initial w (%) is.i
Gs
Void Ratio e
S(%)
Primor
OVC
t(hr)
b,00
0.2
--
1.00
Q.j
2.00
0.9i
.3:
.?:r._
.00
_
0.2
e
o.7
2.,00
01,/1
0.(2.
<
/3.T3
/i .- 1
E(%)
o.820.Z
3?-,L2.
6.-H2.
1 -75
to. 99(.
.
/
2.'. 2.
0. 1
//.
6./
q.q
25.3
/,oo
b.6/
22.9
o.S2
41
.G
/8./0
XI.T3
__
R.w.b.
Tested by
Date .Tuy, 117?
_
e
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M. I. T.
?2.
C/c
7 Units: Svc
Ca(%)
C %)
Coef. of Consol.
It
-
C
j%
Remarks
-_000__
.C
-
2.3
9,00
._.
Total
t (hr)
0
0.42.
21,93
_
2
o.oco
1/5 //.-.
0.oO
,)
P. , P.l.(
w p(%/)
.
3,52.
4.2.
/0.1s
6. 5'/
No. oED-
Sample Height /,143
Sample Diameter 6.3Y/2. cn
COMP,?-e5,8,6/ry
2.?2. WN(%) L l WL(% ,) 7.o Corrections 4PPAgArOS
__--
d.
0, So
l
Ev(%)
TEST
__-/
ul
--
. '/ 3
-.
)( 10-4
-
. / 3 15 1 ? )
5 --
/4.029
x
/9.(0 7
.3- 3_0
-
22.52.-
17.
Remarks
g
v
13AS66
,,
i J F
-R
116
0
5
.0-
10
z
(24.0)
15
I-
20
(2 5.7(2 3.0)-
25
3 0.1
0.2
0.5
2
1
STRESS
CONSOLIDATION
&vC
Sample No.=FIS30
WN(%) = 65.0
Depth = 126.5 ft
W L(%) = 96.0
Soil Type=
wp(%) = 40.6
Orinoco Clay
o At t or
) hr
e At (
hr
5
10
(kg/cm 2 )
Estimated
vo= 2.37 &m =280±0.10
CR=O.330 RR=O.075
P..(%) = 55.4
Gs=2.72 e =l.75 S(%)=101.1
Remarks ev(%) based on dIoo from log timecorrected for apparatus compressibility
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T.
COMPRESSION
CURVE
TEST NO. Oed-16
FIGURE
A-1
117
5
10
z
15
w'
>0
3 0.1
0.2
0.5
CONSOLIDATION
Sample No.= FIS30
Depth = 126.2 ft
Soil Type=
Orinoco Clay
o At tp or
eAt (19.1) hr
hr
' '
'
' ''
a5
1
STRESS
2
&vC
wN(%) =59.8
wL(%) 101.8
wp(%) =34.0
P. I.(%) =67.8
5
10
2
(kg/cm )
Estimated
0: =2.37 &vm=1.6±0.1
CR=0.260 SR=0.090
Gs=2.72 eo=1.695 S(%)=95.7
RemarksEv(%) based on dio0 from log times
corrected for apparatus compressibility
GEOTECHNICAL LABORAT ORY
DEPT. OF CIVIL ENG .
M. I. T.
COMPRESSION
CURVE
TEST No. Oed-7
FIGURE
A-2
118
0
5
10
z
15
I-
20
25
301
0.1
I
I
0.2
I
I
I
0.5
Depth = 128.0 ft
Soil Type=
Orinoco Clay
o At tp or
e At (7.4) hr
hr
I
2
1
CONSOLIDATION
Sample No.=FIS57
I
STRESS
&vC
w N (%) = 66.5
w L(%) = 99.0
w p(%) = 41.9
L
I
I I-
5
10
2
(kg/cm )
Estimated
:o= 2.40 &vm= 2.75±0.10
CR=0.355 SR=0.090
P.1.(%) = 57.1
Gs=2.72 eozI.8OS(%)=100.6
Remarks=ev (%) based on d1oo from log time
corrected for apparatus compressibility
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T.
COMPRESSION
CURVE
TEST NO. Oed-18
FIGURE
A-3
119
-ir
5
FmTT
-
____I
______
0
________
___________
_________
_________
10
__I
z
______
15
I
w.
____
____
20
25
j
________
301
0..1
2
I
0.2
I
II I
0.5
Sample No. = FIS57
Depth = 127.8 ft
Soil Type=
Orinoco Cloy
o At tp or
* At (18.2) hr
hr
2
1
CONSOLIDATION
STRESS
ov
5
10
2
(kg/cm )
Estimated
WN(%)
w L(%)
64.8
990
&VO=
w (%)
41.9
CR=0.245 RR=0.085
2 .4 0
&vm=I.35±0.10
P.l.(%) 57.1
Gs=2.72 e =i.769S(%)=99.7
d, 00 from log timebased
on
Remarks=
corrected for apporotus compressibility
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T.
COMPRESSION
TEST NO.
CURVE
Oed-12
FIGURE
A-4
120
0
5
F-S
10
z
15
w 20
25
30'
0 .1
I -I I I
0.2
i
.L.LL
0.5
1
CONSOLIDATION
2
STRESS
Sample No.= EIS27
WN (%)= 53.5
Depth = 133.9 ft
w L(%) 76.5
wp(%)=37.I
Soil Type=
Orinoco Clay
o At tp or
. At (75.3) hr
hr
i
1 I1 1 1
5
10
I
2
-vC ( kg/cm )
Estimated
2
&v.=2.84 avm= .80±0.10
CR=0.30
SR=O.051
P..(%)= 39.4
Gs=2.72 e =l.58 S(%)=92.3
Remarks = based on d, 0 0 from log time
corrected for apparatus compressibility
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T.
COMPRESSION CURVE
TEST NO. Oed-14
FIGURE
A-5
121
0
5
6-2
10
r(2
2.)
z
15
w.
20
25
(21.8)~
3n
I
0.1
0.2
I
I
I
0.5
Sample No.= EISI
Depth = 83.3 ft
Soil Type=
Orinoco Clay
0 At tp or
0 At (
hr
) hr
STRESS
&vc
w N (%) 6 3 .1
wL(%) =74.0
wp(%) 31.3
P. .(%) =42.7
Si I
I
5
(kg/cm
I
I
-
10
2
)
Estimated
&o=1. 7 4 &vm=1.60±0.1
CR =0.26 RR =0.06
Gs =2.72 eo-
Remarks = based on dI 0 0
S(%)from /t curves
corrected for apparatus compressibility
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T.
2
1
CONSOLIDATION
I
i
I
COMPRESSION
TEST NO.
CURVE
Oed-2
FIGURE
A-6
122
APPENDIX B
CKQUDSS TESTS
Appendix B presents representative laboratory data
from four CK0UDSS strength tests.
CK0UDSS test
tests
One normally consolidated
(No. 9) and three overconsolidated CKQ0UDSS
(Nos. 16,
17, and 18) are presented in tables and
figures as follows:
(1) Tabulated laboratory data.
(2) Normalized stress paths for all overconsolidated
CK0UDSS tests
No.
(Fig. B-1) and the stress path for Test
(Fig. B-2).
9
(3) Normalized stress-strain and pore pressure curves
(Figs.
B-3
to
B-6).
(4) Normalized undrained modulus
(Figs. B-7 to B-10).
Additional laboratory data from CK0UDSS tests is
presented in Appendix C of Ladd et al.
(1980).
123
Sheet I of 2
SHEAR TEST
DIRECT - SIMPLE
PROJECT
HN7rvEP
TYPE OF TEST IK-v7U55
SOIL TYPE
OR/NOnco
TESTED
LOCATION
Fl s"7'
BY
tc(Day)
e
w
Ini ial
6
1 -7 ? /12
TIME
(Hr.)
Th
STRAIN
(/0)
/;30
___
-0c.
CQ
.J-L. .. !
I.coc
0.002.
/.cc,
/.coo
0C000
0-.oc
/._000
0c 4.000
0.02.
0.O0c
/- Oc c
/.000
0.049
.OCl
/-.000
6.0 .3 0.o /.
0.2
-. coo /,000
n.2.e.2
c?.
o.g
o. ZI/
.
1l:Th
is
0./5
2.
___
/2-'0'7
___
___
~f
' a.C58
.?z.
____
0.7o
.9oZ. 0.0
o.s5-of. 0.0
.G92 0./01-.gs'q
c.I!'z
2....
.z
______
____
7-:0(
P'2.'1
0.00- C
c
.o*
.l
ouZ.
0.'/
5-0O. f
0.c0S' c.9?
0."9i(
015
o.;35
.C-77d
o
0.5-21.
p.4/1/
;I./S
/.J/?
05Jbc
.s?
4
o.gt;,
/
2 .
SOIL MECHANICS
DEPT. OF CIVIL
MASSACHUSETTS
0.c
.2
o-G
p.9li
0.os'1
c.1
0.095
o.35"
ni'?
j2j
217
c.9?f
(9
c10.<,/
cX/'2.
o.5-00
2.j1j c.n1.
O. ~ O-./2./
C~t
6-.2
__
____
0.9/4,
o.12o
0..C3
ro0.02..
0
.,(,0
/39
/'______
O.
o./C3
07
.
..
I__-8
LABORATORY
ENGINEERING
INSTITUTE OF TECHNOLOGY
/2./
Is-
jlf
o0.-1
__~___
1.90g'
0.0.
.
n
I
&-.11
9g
0./5-4
____2...O30
0.
0.??2.
c.9tC
C.c5s
0.?3
&,C92 o.97
e,/2.(.
Q.1
n.1
0.
0 -9q5
a./?Q
7L41.
--
.97?
_&
/IW
.Cc a SYYI
5002.
G
c.ot
_.2___
a-.7?
.9
9
__0 _
L 1000
/
o.o 4 9
o.v/5"
|.1
-
-%O.
_
Q.17.9 0.0
vm5
m
1.000
0.05's~
._
0r3 o.
SHEAR
Stress
5.
0.000
0.000
/o
_22:
A-1
Rate (%/ Hr.)
7.
drOc
0002-..
005 6.005
0.023
0.12..
1. / I
.
o 0,00-
4.
0.0001
0.
A"
F o
e. 000
DURING
Controlled Strain
11.399
?.3 1
_vm
ff/.) ?fal/%.CL0 t,(Day) -,-
1-07
I
-
Presheor
IFinal
hc
H/.( )
2.. 0 7 o
S,/
J
95-.
e4,u
(Stressos in ktc/)
7
fvc
1.
DATE
DEVICE (EOA4O
R-14-6
CONSOLIQATION
2-OCR
NO.
Q
.
0. <
REMARKS:
0 3
L;"-
r- 80
124
Sheet 2 of 2
SHEAR (continued)
DIRECT - SIMPLE
4
'^10CO <-A"TYPE OF TEST
PROJECT /WrveP SOIL OR
TIME
Au
3.
=vc
avc
STRAIN
(Hr.)
C
(%)
0.2-4
3.'9 C.l'1
1Q
a1
.S,'?
r'.3I
8. 1 ,
S .5'2
1,-7
1' 70
0.6. -zoo
__
_
_
/5:5o
f2
I9.or.,
o7.7
_
2_
__
/ ._
;.o'9
___.'
___.?
2
4
0 .,
2.i7 o.'3!
.'70
o./3.
2 .4/ .
2.7.073
.
.
0./34
143-970
o.,i'
.Zg.2.1 Z0./3q7
iV.2.5
SOIL
2.*3
0.IQ02
2..2'
Q.C9T
MECHANICS
DEPT. OF CIVIL
MASSACHUSETTS
__
0-4'?
0.15q
CA7
/eL
2.?'/C
n.o,1197
12..0 3.f
O.?
0.o7
.__
0*5
-fg
0.
.
Oo Z
0 ./,6
_
4
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____
_
.217
____
0 . 2.G
____
LABORATORY
_
o-4'3
a5/9
0_
_
____
-I$0
c? 2
1
__
0.34'
o.
0-3Z.0
.370
1
0.02
. cW
2-'0
.
o.z
REMARKS.
TECHNOLOGY
_
_
_
_.__
I
0./
_
_
__
__
o./ o
_._
_
0.1____54
C
0.0. /9
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0 -'Z70
ENGINEERING
INSTITUTE OF
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0.507
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a
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C.-4
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c.C
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0.490
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0.
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1:o
/ .'2?
z.T,3R
/IT: 3(_0 0, .l q
/
-
vm
0. o2.0
.
-4
00.2j 0 0
__L
vm
U
0,700
0.1j19
c.lt
/O.2A
./34
C.3/1
_____
i.
lh
0.820
0.7
o.Zf'- l
o.0
/_?7L/1
?.l13
7z.4
S.
'7 2.
LNO.
__
__.:__
__ __
__d
_
125
Sheet I of I.
SHEAR TEST
DIRECT - SIMPLE
PROJECT ILTIE/P
TYPE OF TEST C
SOIL TYPE9L . ".o
TESTED
DEVICEGE COR DAT E
2-
vc
Thc
TIME
STRAIN
Hr.)
(1/0)
,/'Ls
Th
in
o
-. t
.i3(
0,7;i
1221
/
2.ol.74
'_
O.32.(
././
-0.215
*, //3i
a.29?
Z. /O
7 214r
/
.rh..
c
/.- ao 4 l
2
/
-0.o1
/,109
0-
0-010 0So,4
__-j.T 4
.C015'
,/77
0.32.-7
-0.072
... n-.07n
--. 04t
at
-
o I.'
17'./T
-77
no 07
0./6'
y 7.45
.24 .. reI 0.2zTZ
127,407 /0. 20C T
SOIL MECHANICS
DEPT. OF CIVIL
MASSACHUSETTS
0. t7l
.-
o.3Zj
85 0.905'C
0,jo5
-30q
LABORATORY
ENGINEERING
INSTITUTE OF TECHNOLOGY
.
_
_
c> -5c 20 -2 5.
n 4'_.
6-5 4
0.,7-1
1'^./60 n - IqO
7so
0-72
151o e4/9 7 ,
-,./27
c).4 17
10- cof
0,
_7
/t-_It
1.3-5/2
")/34
.. 3o
a
^_Ze7
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2
^O,
0- S
j.
2
IO I?
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7q,3.
24. /0Z-
2.0.
i .
,
_7 /
111
.
--
Q0A
_s__ __6;
O.92o q ./3 3
0.0( O--
272 0.',116
/ 0.
I
,
3
n.067
7
?
/,/
Y
o.sCo7
10.t4
A,072
I 0.
I0-o29
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-ej .
000Oi'
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C 77
--
O._ 1-cq
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-
jF
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,. .
/
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r m
0-o .c
/.ooo
j
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..
2 ./7 /4 0? 7
0.313
0.?z.o-17 oS97
7-11.1y' o."3.//. 023 S .10 .?
H. 31?
/.
/.ooo
0.-17Z- .- -V
%'11
_
o~c
-
0.207
0.27
S. b
Rate 0/%/ Hr.)
7
0 - .00G.
-3,
1 -.. /
1
0o~c
no ccou
-
(Day)
DURING SHEAR
Controlled Strain '--'' Stress
-1v
0 - ./57 0. -3(
1
-
A&L
CO(Oo
O.oo0
n, 24
( ,m)
-p
'Fe
n,025, 6.nzo
o-OSS 0.6 0
_
2
'/-7 3.1(0
Psin ihi ar -0,9
/4
71, 1
V.D / . 6
Preshear
Final
H
S,%/o
_
C(%).-
erf.) /X:.
fc(Day)
w */ Ie
)
(Stresses in
CONSOLIDATION
7
LOCATION
BY
OCR
NO.
/Z. 3
REMARKS:
10.n q.C .2 .5 .
126
Sheef I of I
DIRECT - SIMPLE
SHEAR TEST
PROJECT
INE\E/?
TYPE OF TEST C
SOIL TYPE
C4
TESTED
BY A a
Tvc
fc(Day)
W,%
(i. 2
/-
Preshear
Final
--
/
TIME
27,
-171
.
I
STR AIN
Th
(%)
Fc
(Hr.)
o.olg O.0
4
0.0
?( o~n
0.3:';4
I
/
O..
I
o4
Vm
---
.
!.40
-/?V
___
0.i 'j14
-216
1*
IT 1 .
/il
,
/_&,
/./4/ .4
o.2
173
-
3
-
1,j
-c
M
:
.
.3q0
/
3V4f
f
SOIL MECHANICS
DEPT. OF CIVIL
MASSACHUSETTS
0
9 1. /2?
(,0 Ir" 0/1
-1~
7,
_
n0
2.3
9
_
.
.3 Z o
.3)31 C
9
c.
n.IK
0.1
2
0f
9o/(.
LABORATORY
ENGINEERING
INSTITUTE OF TECHNOLOGY
a. 3
0
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13% 0.0 ,D 34;2
0,/3?
- j 6, 0.4O
0 -11
21 0.09-2Z j.
17'.lo~~~~~~~~~
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05
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/cM
2
350
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2 D
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3/-.9-,/ >.(,/95- 0OP7
3.77K& 0. 40-4 -o.
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229
6 . /4'2- 6 .4'-, f- 0. . .1
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0-14
I
"V
C~r..
0C-coo
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3-
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1.02L.
-. 0V 7-3
7o i-C.
6.2(5
n
/
F _
vc
/-
tc(Day) /A 0'
DURING SHEAR
Controlled Strain
Stress
(C.)
/,ooo
c-0*6
-o-i;,
._/
_
Ep/.) 4-:.. fc(%/)-
-
/ceo
_o
- DATE
Rate (% / Hr.)
A_
avc
o-coco
3.1
OCR
DEVICE
I% I~I7I. u.I4 c
~
-oo
'7
_hC_
H
6
Initial
NO.
(Stresses in
CONSOLIDATION
7
LOCATION
utD-
.39
0~ -, /2/ 3/ q
o i
REMARKS:
Pg
1
.
_
/3/
127
Sheet I of
DIRECT - SIMPLE
lMT)JE
PROJECT
c
SOIL TYPE
TYPE OF TEST
TESTED
A
NO.
BY
rhc
-
-M/7% S6
Presheoar
70o
) ^
2.0
-----
DURING SHJEAR
Controlled StrainStress
i
(
STRAIN
Hr.)
T1
(s%)
/L:.
0'e, il
0.1
a
(:4r o. 4
7Z2
S/./5/
n.
.
-0.-S
0.
"1 - 0.194
0-3S4 -
~o5 o.37
___/,
3.
0.54/
IW_3_ 0./
'o O.??
7./7/
3
/3:
,
r
31
_
-
oL~
7
7 .5- 1
7
/6,
5.7Y-
196
e
N
/
a.
L,41I2.
0O RS
oo
- a ..
-e-6,
41
j/,7~ 7't
5
-
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/0 S
(
-0
./I
.03
(N
,7
II
c
11
L
o,~,
___
0.
. 2/0
3
_
.23
() . 4 0.010 0; 115
o .0
0-41 c
5 _a 2ol
o40f 1,0 t
385
LABORATORY
ENGINEERING
INSTITUTE OF TECHNOLOGY
_
0at TYo, I.191
REMARKS:
19
1
3
01
_
7
-i23i1
2L
-41 1
64.
/ . 2-71 - 0
5
/ 1__._1
1 /0
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0.,21
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Yi
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4).?/ / 6. 5 7 -6.9
/','7
22.3, 0 - T'f-D - 0,q / I
o Z'3., Y.2
r>.71 11. '171Q
SOIL MECHANICS
DEPT. OF CIVIL
MASSACHUSETTS
a,6 012 r
.1,
7
/72
/Ii/n
_____
-t-3
&
-.
.
_
_
2
.. pOJ/g
6- jl6 . ./ 7"
b.0. /7 3
.i.
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- .331 In g 32 0./q=
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-
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4_7
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-
/ L
-6,
6. 7'
/,___o-
_ _
c.,
jal 1
n. /42
/.
o
r.,13 3
____
.
movm
-
.9
6't g.47c
- .3012 ./. 2 o ; 0.537
Y o.5' -o.330
/,332
t -/. ?
.2.
36
lo
0
IF
n
c z
'.
jq 0.N -o.u /,4q Oqo
0.0339
t h
vm
O.C94
0.06a
0.
O7
Fvc
T
T
M
.A
3.?
V%/ Hr.)
Rate
Fina l.
TIME
(DARy)
OZ.)tDING
H
D.4,
.
Igo
vm
-
c(Day)
w % e S,%
7-~70
)
(Stresses in
4vc
Initial
OCR
1
DEVICE GEO102C. DATE
CONSOLIDATION
7
LOCATION
SHEAR TEST
I~
__
Test
No.
Sample No.
Depth
wN
(f t)
(%)
&Vc
6vm
OCR Symbol
(kg/cm 2)(kg/cm2
7
FIS24
96.5
61.0
1.72
2.40
1.40
0
5
EIS21
98.8
60.2
2.02
4.00
1.98
0
4
EIS21
99.8
57.0
2.50
5.00
2.00
A
F S'1
I11(.1
4.
1..1
l.f
0
115
7.
v
_ ____
I9
.E
o '1
6a. 1.0-;,
FIS
_________
1o
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR., M. 1.T.
0.4
0.3
H
t'J
0
rh
0.2
0.1
0
'1
0
0.1
0.2
0.3
0.5
0.4
0.6
0.7
0.8
0.9
:0
mn
to.
v
NORMALIZED STRESS
BORING
-
vm
PATHS
SOIL TYPE
FROM CKOUDSS TESTS.
ORINOCO CLAY
1.0
Test
No.
Sample
Fic,97
S
0.4
liii'
0.3
Illlli
Depth
D%)
No.
(
Ii ll I
Illllllllilllllilllllllllll
itoi
4ij{
In,
li-ti
If' "ii, Ii' iiii:J~
I. iii
Ii
0.2
IDI
Fl,
lID
th~
ii' li-n ~i1ii" 'In
i-Li
Ii,
Jilt
I'
!
ill'
,
fiT Fi~
"I
III
L
Ii
0.1
14
I
- ---
0.1
0.2
0.3
GC
P1
144
ill
$it
If', 'i-f,
~ti
fin
ifl~
1I
14t
444
NORMALIZED
ii
L1
iii
0.5
0.4
/
I';
i;;,144441
In,
'Ut .1
ill' I I' ff1-I
Iii~
~I
Ii ftD t in K
-lilt itt IJiF
I,,
liii
ii'ii
0.7
till
Ii'
I'l
LI liii
0.8
STRESS PATHS FROM CKOUDSS TESTS
O^-w(
to
4
'flu
liii If"iL
0.6
I 44
iy~
Hi
vm
Soil Type C
I
4,-
Ii
'if
4:4
ff1'
it"
ih~ Im1
Ii
it,''
hi
lilllllllll "''Il II
ii-:
ILI-
t1
44
DEPT. OF CIVIL ENGR.
M.I.T.
Illll
i~If"
'Jai ,11if
av
Boring
OCR Symbol
GEOTECHNICAL LABORATORY
14~
--
0
ii
tEL.
'11
0
Ovm
.
//.
44;
6vmn
&vc
d(,OE470 -o-
1~i'Li
I~1j
iii-f II~i
I 'if:1 iD-f
~'IfI
Th
-Ti
wN
(A
0.9
iii~
1.0
130
*........................----
----- - - -
itsr
-----
-
-
- -
-------
~~
4:
77~ -7-
0
vh
t:
cVC ,
... .....-.-
..... ..... .
-- ----
--
.0
1.
------
... ... ..
--
.. .. . . . .. .. .
.. ....
C
.2
:. ..
..
.
...
..
.....
:7 - 7
Au
rc.
n
. .. ...... .... ....
5~.
2..4
..-..
0
0
5
10
15
SHEAR
Sample No.
Depth(.)
Soil Type C
/2.L
00
STRAIN
20
40
X' (%)
wN
&vcN(%) ('z' A 12
t c(Days) -L>
wL(%)
& Svm(4/
OCR /o
c wp(%)
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M. I. T.
I
)
Estimated &*o(A //
NORMALIZED
STRESS
CK.UUDSS TEST
VS
NO.
) -.
STRAIN
7
FIGURE
B-3
131
I
0.&1
4jK.p
-..
7Lt-
Th
I',
---ii7:
T-T
----
-T Ti
yT F ET
----
----
t
H:p
. - -- -
...-
-..
.....
.
.. ... .........
4
-..-.
7-p
...
b.777t
:-- ...
...
A
....
.. .
. . ..
..
...
.
-.7i
VC
-...
...
..
... .........
..........
'A
.. 7~~_
::: 77:
:71
. ...
__ _
0
0
10
5
15
SHEAR
Sample No.
r+)t
FWs7
O--o
w p(%)
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T.
STRAIN
0 .cI
w L(%10'
/zF
Soil Type C
C
WN(%)i
20
A
avc(
Y (%)
/,-z
a vm(/
)2210
tc(Days) C-9
)M
OCR /?PC
Estimated aGo/
U /
NORMALIZED
CKoUDSS
STRESS
TEST
VS
NO.
) 2/
STRAIN
___
FIGURE
B-4
132
-
-
--
-----T
K
,
H
-
--
-
- ---
+--
H
Th C
5
~vc
77--
7 p
*
:4 -
:=.
- rz:*
O.z
0
5
0
10
F
15
-..F
....
20
-
_A_
t--7
-....
u
.. . .. . .
o-.v c
7 .
... ...
.......
.. .. . ... .
... .
..... .
-..
.) .4
0
5
10
15
SHEAR
Sample No.
Depth(#)
Soil Type
20
STRAIN
2r (%)
'S 7
wN(%)
k'
-
wL(%)
o&vm(6 /~2
/4
-
w p/(%)
_
( d
40
3w
-
Estimated
)
tc(Days)
R
) 2l
avo(k
C-Q
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T
NORMALIZED
STRESS
CK.UDSS TEST
VS
NO.
STRAIN
/7
FIGURE
B-5
i
7/
133
.. ..... .. .
.... . .
tr
1::. :j 7 7":
7-
. ....I ....
t
.... . .. .. ... .. .
I
---- --------------.
.... . .. ....I...
:
7:-_:
-----
.... .....
t77:::777-
........... .......
.. ....I--.-
.... ......
.... .... .... ....
.. ....
-:1:7
7
"-t-=7.'
---------
=7
Th
O'vc 0.4
Z-4
7---
:r7=
J:7-
at
---------- ------------------- ---...............
------ ----- --
.7+
0.2.
:7.:
HH..=
tt,
0
5
0
0.0
........
:% _"1::: .
10
4C
...... .........
...... ..
.........
...... 1' -11'
......... ......... ......... ........
'-7 7:t:
.I .... ........
... ........ 1 ........ 1.. --: .....
....... .. ....- --------..... :..
. - --j .. .....
.... .........
. ........
......... I -------......... .
.......... .
--..
.: -:
.........
---- ------------- : ..... .... ..
...... ....
...... .........
. .......
.......
... .........
-7
.. .... ......
z.::
.....
:-:1 7=
7 .. ........
.... .........
0
-30
... ....I ....
.........
.....
c'vc
20
....
....
................ --------......... .
..................
. ..........
-------....
......... .. ....
...
......
. ......
- -,:::::
. ......... .........
.... ..... ..
Au -0-,j
15
...
7-7.
....... ....
......
--------- ----
..... .........
.. . ... ....
...
.........
.... .........
--------
5
10
15
SHEAR
Sample No.
Depth (;4
Soil Type c14 (0,4-4f-
---------.... ..
..
20
STRAIN
... ....
-W
7a
a' (%)
WN
evc(/z4
wL(%)
a:vm(
wp(%)
Estimated &vo(/C
4er
2-T
tc(Days)
0CR
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M. 1. T.
NORMALIZED
CKOUDSS
STRESS
TEST
VS
-7. 7 0
STRAIN
NO.
FIGURE
B-6
134
2000
411 i
i fi
i ii
H I,+
ii
I
iI
I
1000
Soo
600
400
Eu
su
200
I
(IN
+11
100
z
I
II
! 1 1 it
11 ! 1
j 1 ,
80
60
0
40L
1-;
0
w
0.2
0.6
0.4
0.8
1.0
rh /Su~
0
Ix
Test
No.
0
___
Sample
/-_
No.
_S-7
Depth
wN
v
WN
V6
/.)'G5~
Symbol
OCR
o
.
- 0-
0
z
(D
NORMALIZED MODULUS
FROM
BORING
TYPE
zl
SOIL
CK.UDSS TESTS
c
< C-Q
FIGURE
B-7
135
2000
1111fi-1-11
I
!! ;I
I I I I I I I I I
L
I I
I
i
I
I
I
ii
1000
I I 1
1.
~*jiI
Ij
II
II
800
600
400
Eu
Su
200
I
I
III
'I
II
100
z
i
I
11
MI
I
I
80
60
-
0
CL
40 L
0
0
0.2
0.4
1.0
0.8
T'h /Su
0
Test
No.
w
0.6
wN
No.
Sample
5'i7
/S
Depth
/2 .3
v
VC
WN
(o).
OCR
6
2-;J,0
Symbol
-Q
0
0
NORMALIZED
BORING
f.
MODULUS FROM
SOIL TYPE
CKoUDSS TESTS
O
ke-
e
FIGURE
B-8
136
2000
II
I I
I I I I
I
I) I
I
i 1
ii
i
I iI I
I
+i1.11
i IL
7tI
1000
800
600
400
Eu
su
-
200
0
I II
100
z
w
111
I
~
I
I i
80-
-
60
0.-
F
40
a.
-
0
0.4
0.2
0
.a
0
0.8
0.6
1.0
Th/Su
Test
No.
Sample
17
F-/__D-~7
Depth
No.
WN
g VC
OCR
Symbol
/'/
SAI
---
co
ca
V.2
_/2.
/
0.
w
4
NORMALIZED
BORING
MODULUS
LL
FROM
CK.UDSS TESTS
SOIL TYPEC4 O
-
CFIGURE B-9
137
2000
~I[F
I II
I
I I
1000
I I
L!
17 -1,
tt+-t
I
..; I
II!iili
ii IF i~
4+4
I
j
I
i I I
'I .'
800
600
400
Eu
su
200
!I
I ! I
i
II
I I I i i
I I ',Ii
1 1 1 1 1 1 1 M 1
I
z
;
L
I
II I I I
1 1 1 !-q 1 1 I M
N
100
C9
ltII
I i
i!
II
; i i
,
I l ! ;
i
I j ! I i
i , !
I I i
i ! ! 1 1
7
i I : ;
i I I
80
60
U0
40
0
0.2
0.4
0
1.0
Th /su
0
uJ
0.8
0.6
rest
No.
Sample No.
/___
Depth
wN
v
WN
YC
OCR
Symbol
o.si
770
0
/2./t. ( .
__/____
I.-
0
a:
0
NORMALIZED
BORING
F1
MODULUS
FROM
CKoUDSS TESTS
cLCla~4
SOIL TYPE C'a
FIGURE
B-10
138
APPENDIX C
CK UC AND CK UE TESTS
0
0
Appendix C presents laboratory data from CK UE and
CK UC tests.
The following data is summarized in this
appendix:
(1) Figure C-1 presents the stress paths for all
triaxial tests.
(2) Figure C-2 presents the stress-strain curves for
all triaxial tests.
(3) Laboratory data from CK0UC Test No. TC4 is
presented in the next two tables.
Additional information concerning pertinent test
procedures can be obtained from Appendix D of Ladd et
al.
(1980).
z (ft)
0.3
0.2
TEST
SYM.
BORING
No.
WN
Pi
(%)
(%)
99.1
99.5
TC3
TC2
0
A
El
El
57.4
51.5
39.0
31.5
128.7
TEl
O
Fl
60.1
57.1
I'l.3 TV
9
Fli
61.8
519
I24.5
,
27.
-
0.I
q
crvc
0.0
0.1
0.2
0.3
-0.1
FIGURE
0.5
0.6
0.7
0.8
OF
q= 0.5 ((V
-0.2
0.4
-
Oj)
.
p=0.5(&,+-
C-i
STRESS PATHS FOR CK UC AND CK0 UE TESTS: N.C. ORINOCO CLAY
0.9
1.0
140
0.
0.
z (ft)
TEST
99.1
99.5
128.7
1 .3
TC3
TC2
TEl
Tc
SYM.
BORING
0
a
El
El
Fl
F1
No.
.
v c7 iO
0
V
wN
(%)
pf
(/)
57.4
51.5
60.1
GIA.
39.0
31.5
57.1
g.9
-0. 4
-0. 6
0
I
2
3
4
5
6
AXIAL STRAIN , e 0 (%)
FIGURE
C-2
STRESS VERSUS STRAIN FOR CK UC AND CK UE TESTS:
N.C. ORINOCO CLAY
7
141
Sheet I of 2
CONSOLIDATED - UNDRAINED
Project /AWfF E?
Soil Type C &
,
TRIAXIAL
Type of Test C .OLocation
FISS7
TEST
No. TC'L OCR /LQ
Tested by A w.
.A/Lf
Date
Stresses
in
UB 26.
/
,i
w (%)
Initial
16 4 7 77
T./9 7 71/
avc
&hc
0.80.1% /.q
0.
S(%)
0.0q
C Vol M%~
.7&/
C0
%
0
.;"/ 11
( v-
0
vc
V_ /
0.74 A
.
o
.7
/S-g
y
o,4
tc (Day)
(h)
'??37 1.1
1 . 23
.9
h)
.*S
9
.'-oo
/0
/.
-
27;
& S
2-0t
2,11
. 77 Iq
11
Eu
qf
c .77
0,7'17 /7f 5
0 -o 0 ' o.794
5,32
Z.&91
1
1.29 29 7
4
.2q76 o ?
/-37
.'
0-20?
. 37
0 4.o)7
2' 0,(711.3E
..
w:7 -D .2
____
y
_____
.9j o.
0. : '.?
, ). 74 n -25
n7 .7
1
.1149
0,Z6
1,t '7
:A;
7~' n. -%
!s
,5177
5 -T1
76" 2. 1 t
1
m.7
q-io o 177 g. z-.o
T.3 7 02c~o .5 0 , 24
-41,4
1.L.Sl >-2
6S C q -,197 1.7-.A34 0517 121:1-4
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M. I.T.
10
--
&v-
O.2
n. 6,1
G2 .s40
/
0-l 10
1? . rTl
0 -~ Q
.(
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C 7 .2-,9
32 0 5 0 -. 1
9
1
A
.
14. 7
9
q
A
4 .4z I0 o-5o 9 n. psa(I
"1
4,3,
C, 5
( . 02
114
-
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&h
I
8
./4g
u-a
&vc
4,9
/.71
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111 11/c 7
o.
7
2.-1.
g /,477
0oa Qo .qi 0-ooi /-7//
q~s .44G.1) -0-3
0.472 0.00
7
-
(
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/ .4
/.7.
7
7 23 NcJ O 2 ,
g.82
-) 7jL C,.j'.j
4/-
/
wp M 3 7.4. PI.(%M2.,1L
WL(%M V.
CONSOLIDATION DATA
2
3
4
5
6
Step
Time
Strain Rate (%/ hr)
Remarks TV O.4r
L(cm) A(cm2 ) V (cc)
e
61-
Preshear
B (%)B M
..72.T
C "
/
.70-2
0.477
,7
L- 6 S
OC41
ILA"
e-4
e.ota-
Lk~s
142
Sheet 2 of 2
CONSOLIDATED -'UNDRAINED
Project Aj!VP Soil
Time
(hr)
ea
.
(%)
TRIAXIAL TEST (continued)
Type of Test
~
(
A
(Au-A
(Ov'-G6h)
&vc
A
C. 373
4:__
2.rco Ojfj
A-2o
I..'7 o.'o
To 4 0.u ZE ,M
9
793t
W, q
n
2.
f 7,.
'
No. 7C4
-
&h
a6vc-
CA- uc.
_c
.3'
3% /.?60 (. .;a
/.
. / 92
6.01
O
4
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/ 0,S v 5.(%
.7
&-15-.(
e's /7 a-
n, 0.
n. -;- I
o. 179/
_
_,_
GEOTECHNICAL LABORATORY
DEPT. OF CIVIL ENGR.
M.I.T.
A-(SLLDA~
A
-2-1