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1
CE2112: Laboratory Determination of Soil Properties and Soil
Classification
Laboratory Report
G1: Index and Consolidation Properties
G2 Shear Strength
Year 2013/2014 Semester 2
PENG LE
A0115443N
2
Table of Contents
1. Executive Summary ................................................................................................................ 4
2. Overview .................................................................................................................................. 5
3. Atterberg Limits Tests ........................................................................................................... 6
3.1. Principles ............................................................................................................................ 6
3.2. Plastic Limit (PL) ............................................................................................................... 7
3.3. Liquid Limit (LL) ............................................................................................................... 8
3.4. Classification of the Soil .................................................................................................... 9
3.5. Discussion......................................................................................................................... 10
4. One Dimension Consolidation Test .................................................................................... 11
4.1. Principles of One Dimension Consolidation Test ............................................................ 11
4.2. The Result of One Dimension Consolidation Test........................................................... 12
4.3. Casagrande’s Method to Determine cc, ca and pc’............................................................ 13
4.4. Casagrande’s log(time) Curve Fitting Method ................................................................. 15
4.5. Summary of One Dimension Consolidation Test Result ................................................. 17
4.6. Discussion ........................................................................................................................ 18
5. Shear Strength Test ............................................................................................................. 19
5.1. Principles .......................................................................................................................... 19
5.2. Wood's Semi-Empirical Relation ..................................................................................... 20
5.3. Laboratory Vane Method ................................................................................................. 21
5.4. Penetrometer Test............................................................................................................. 22
5.5. Undrained Triaxial Test ................................................................................................... 23
3
5.6. Summary of Results for Three Samples........................................................................... 30
5.6. Discussions....................................................................................................................... 31
6. Assessment of Data .............................................................................................................. 32
6.1. Correlation of Atterberg Limits Test and 1D Consolidation Test .................................... 32
6.2. Correlation of Atterberg’s Limits Test and Tests for Undrained Shear Strength ............ 33
6.3. Comparison with Existing Guidelines.............................................................................. 34
7. Recommended Design Parameters .................................................................................... 36
APPENDICES .......................................................................................................................... 37
Appendix I: Test For Liquid Limit (cone penetrometer) and Plastic Limit ............................ 37
Appendix II: Water Content/Bulk Density for Consolidation Test......................................... 39
Appendix III: Calculations for Casagrande’s Method to Determine cs,cc and pc’ ................. 41
Appendix IV: Graphs and Calculations for Casagrande’s log(time) Curve Fitting Method .. 43
Appendix V: Water Content for Shear Strength Test ............................................................. 48
Appendix VI: Calculations for Wood's Semi-Empirical Relation .......................................... 49
Appendix VII: Calculations for Laboratory Vane Method ..................................................... 50
Appendix VIII: Calculations Pocket Penetrometer Method .................................................. 53
Appendix IX: Data and Results for UU Triaxial Test Result and Analysis ............................ 56
4
1. Executive Summary
Here is the summary of the recommended design parameters.
Table 1.1. Summary of Design Parameters
Parameters Values
Plastic Limit (PL) 36%
Liquid Limit (LL) 90%
Plasticity Index (PI) 54%
Soil Classification CH
Compression Index (Cc) 0.280
Swelling Index(Cs) 0.0325
Pre-Consolidation Pressure (Pc’) 186±10 kPa
Coefficient of Volume Change(mv) 6.0x10-5 ~ 1.2x10-4 m2/kN
Coefficient of Volume Change (cv) 0.8~3.0 m2/year
Permeability (k) 3x10-11 7x10-11
Undrained Shear Strength (cu) 23.6 ±3.0 kPa
5
2. Overview
Here is the summary of the tests done to find the parameters.
Tests Parameters
Antterberg’s Limits Test Plastic Limit (PL)
Liquid Limit (LL)
Plasticity Index (PI)
One Dimension Consolidation Test Compression Index (cc)
Swelling Index(cs)
Pre-Consolidation Pressure (pc’)
Coefficient of Volume Change(mv’)
Coefficient of Volume Change (cv)
Permeability (k)
Wood’s Semi-Empirical Equations Undrained Shear Strength (cu)
Laboratory Vane Method
Miniature Cone Penetrometer Method
Triaxial Test
6
3. Atterberg Limits Tests
3.1. Principles
In Atterberg Limit tests, Liquid Limit (LL), Plastic Limit (PL) and Plastic Index (PI) are obtained,
which can be used to classify the soil.
7
3.2. Plastic Limit (PL)
Plastic limit is the minimum water content at which soil can be deformed plastically. To
determine it, a soil sample (about 20g) is taken and rolled into a thread repeatedly using hand
until slight cracks to appear as it thins down to about 3mm. Then the water content at this stage
is measured and this value is the plastic limit. The plastic limit for this soil sample is 36.41%.1
1 The detailed calculation can be found on Appendix I.
8
3.3. Liquid Limit (LL)
Cone penetration method is used to determine the liquid limit. A cone is penetrated into the
sample and the penetration depth of the tip of the cone is recorded. The above steps are repeated
for 4-5 times by keeping the penetration depth in the range of 15-25mm and the water content is
determined for each trial. A graph of the cone penetration depth against the water content is
plotted and the regression line is obtained. The water content corresponds to 20mm penetration
depth in the graph is taken as the liquid limit. From the experiment, the liquid limit for this
sample is 90.72%.2
2 The detailed calculation can be found on Appendix I.
9
3.4. Classification of the Soil
The following result is produced in our test:
Table 3.1. Summary of Atterberg Limit Test
Plastic Limit (PL) 36.41%
Liquid Limit (LL) 90.72%
Plasticity Index (PI) (PI= LL-PL) 54.31%
Using Plasticity chart for laboratory classification, the soil sample should be classified as CH.
Fig. 3.1. Plasticity chart for laboratory classification of fine grained soil
Soil Sample
10
3.5. Discussion
The test on the PL is not very accurate as the judgement of “start to crack” and 3mm is very
subjective. This may be improved by making more trials and taking the average. For the liquid ity
test, soil may not be thoroughly mixed and the value of water content may not be. Also, 4 values
may not give a very good estimates and more tests can be done to improve the accuracy.
11
4. One Dimension Consolidation Test
4.1. Principles of One Dimension Consolidation Test
In one dimension consolidation test, the soil sample is constrained so that it can only settle axially.
Different loads are added from day one to day five and the change in height of the soil samples
are measured. The void ratio and the void ratio changes can be calculated using the following
equation:
∆𝐻
𝐻=
∆𝑒
(1 + 𝑒)
The value of coefficient of volume changes 𝑚𝑣 can also be calculated using the following
equation:
𝑚𝑣 = −∆𝑒
∆𝜎𝑣′(1 + 𝑒)
The load added is summarized in the following table.
Table 4.1. Load for Compression Test
Day Load/kg
1 20
2 40
3 80
4 160
5 40
12
4.2. The Result of One Dimension Consolidation Test
Table 4.2. Results of 1D Consolidation Test
Day Load/kg Stress/kPa Height
(H)/mm
∆H/mm ∆H/H ∆e e 𝑚𝑣
/𝑘𝑃𝑎−1
0 0 0.000 18.580 0.000 -- -- 0.883 --
1 20 52.523 18.517 -0.063 -0.003 -0.006 0.877 6.478×10-5
2 40 105.045 18.372 -0.145 -0.008 -0.015 0.862 7.513×10-5
3 80 210.091 17.965 -0.407 -0.022 -0.041 0.821 1.078×10-4
4 160 420.182 17.138 -0.827 -0.046 -0.084 0.737 1.148×10-4
5 40 105.045 17.358 0.220 0.013 0.022 0.759 1.207×10-4
13
4.3. Casagrande’s Method to Determine cc, cs and pc’
In this method, the void ratio of the soil is plotted against the log(time). The slope of the virgin
compression line gives the value of cc while the slope of the swelling line gives the value of cs.
Legend
P Point of maximum Curvature
CD Straight Line Backward from Virgin Compression Curve
PR Tangent of the Curve at P
PQ Horizontal Line Intersects P
PS Bisector of Angle QPR
Fig. 4.1. Graph of Casagrande’s Method to Determine cc, cs and pc’
The value of pc’ can be obtained using the following method:
1. Locate the point of maximum curvature P.
Logarithm of Effective Vertical Stress, log (σ’)/log(kPa) V
oid
ratio,e
14
2. Project a straight line (CD) backwards from the virgin compression segment of the curve.
3. Construct the tangent to point P(PR) as well as a horizontal line(QP)
4. Construct the angular bisector PS to the angle QPR.
5. Locate the point of intersection between PS and CD. The abscissa of this point of intersect ion
gives the pre-consolidation pressure.
The results are summarized in the following table.3
Table 4.3. Values of cc, cs and pc’
Sample
𝑐𝑐 0.280
𝑐𝑠 0.0325
𝑝𝑐′ /kPa 186.2
3 Detailed calculation can be found at Appendix III.
15
4.4. Casagrande’s log(time) Curve Fitting Method
In this curve, the void ratio is plotted against log(time) to found the time for 50% of the
compression to occur 𝑡50 . The value of coefficient of consolidation cv is calculated using the
following equation:
𝑐𝑣 × 𝑡50
𝐻2= 0.196
Fig. 4.2. An Example of Casagrande’s log(time) Curve Fitting Method
16
Here is the value of 𝑐𝑣 obtained from this method.4
Table 4.4. Values of cv
Day Load/kg
𝐶𝑣/𝑚2𝑠 −1
𝐶𝑣/𝑚2 𝑦𝑒𝑎𝑟−1
1 20 2.815×10-8 8.88
2 40 9.780×10-8 3.08
3 80 2.621×10-8 0.83
4 160 2.506×10-8 0.79
5 40 5.313×10-8 1.68
4 Graphs and detailed calculation can be found in Appendix IV.
17
4.5. Summary of One Dimension Consolidation Test Result
The result of the 1D consolidation test can be summarized below.
Table 4.5. Summary of 1D Consolidation Test Results
Day 𝑚𝑣/𝑘𝑃𝑎−1
𝐶𝑣/𝑚2𝑠 −1
𝐶𝑣/𝑚2 𝑦𝑒𝑎𝑟−1
𝑘/𝑚𝑠−15
1 6.478×10-5 2.815×10-8 8.88 1.824×10-10
2 7.513×10-5 9.780×10-8 3.08 7.340×10-11
3 1.078×10-4 2.621×10-8 0.83 2.825×10-11
4 1.148×10-4 2.506×10-8 0.79 2.877×10-11
5 1.207×10-4 5.313×10-8 1.68 6.413×10-11
The cv and k values decrease with increasing load and increase with unloading. When the soil is
loaded, it becomes more compacted and less permeable. During unloading, soil becomes less
compacted and more permeable.
5 Values of k is calculate using equation𝑘 = 𝑐𝑣 𝑚𝑣𝛾𝑤.
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4.6. Discussion
The void ratio of the sample after the test is 0.753,6 which corresponds to the final value of e (0.759)
from the calculation from ∆H and H. Thus, the calculation in section 3.2 is quite reliable. However, the
graph fitting in part 3.3 and 3.4 is done by eye, which may not be very accurate. More accurate analysis
may be done using graphic analysis software.
6 Details to be found in Appendix II.
19
5. Shear Strength Test
5.1. Principles
In the experiment, four different tests are conducted to evaluate the shear strength.
20
5.2. Wood's Semi-Empirical Relation
In Wood's Semi-Empirical Relation, the remoulded shear strength of a soil can be correlated to
its Atterberg Limits and water content by the following equation:
𝑐𝑢 = 170 × 𝑒−4.6 𝐿𝐼
Where LI is the liquidity index given by:
𝐿𝐼 = 𝑤 − 𝑃𝐿
𝑃𝐼
Where w is the water content
PL is the plastic limit and
PI is the plasticity index.
Using the Atterberg Limits obtained above, the 𝑐𝑢 value from Wood's Semi-Empirical Relation
is 26.22 𝑘𝑁𝑚−2 .7
7 Detailed calculations can be found in Appendix IV.
21
5.3. Laboratory Vane Method
The test apparatus consists of a four-bladed cruciform vane on a rotatable shaft. The shaft is connected
to a device for applying torque to the vane with a scale indicating the value of the torque applied.
The soil sample to be tested is held direct beneath the vane. To measure the shear strength of the soil
sample, the vane is lowered and pushed into the sample until it is completed embedded to the required
minimum depth and the depth of penetration is recorded. The torque is then applied by rotating the
motorised torsion head until the soil start slipping. The maximum torque applied and the angle of
rotation of the vane at the instant of failure is then recorded. The shear strength of the soil is given by:
𝑐𝑢 = 𝑀
𝜋𝐷2(𝐻2 +
𝐷6 )
Where M is the applied torque,
D is the overall width of the vane, and
H is the length of the vane.
The results of the test are summarized below.8
Table 5.2. Data for Laboratory Vane Method
Specimen
Vane No A232 N2
Initial angle (o) 252
Final angle (o) 329
Angle of rotation (o) 77
cu (kN/m2) 29.79
8 For the detailed calculation of the results, please refer to Appendix VII.
22
5.4. Penetrometer Test
This test measures the bearing capacity of the soil beneath the cone. In the test, the tip of the
penetrometer is set to bear against the soil surface. To raise the bearing stress on the soil surface,
the load on the penetrometer is gradually increased. The process continues until bearing capacity
failure occurs and the penetrometer starts to dig into the soil. The maximum load thus measured is
the bearing capacity of the soil. This load is related to the undrained shear strength 𝑐𝑢 and the value
of 𝑐𝑢 can be read from the pre-calibrated graph. The result of the test is summarized below.9
Table 5.2. Data for Pocket Penetrometer Method
Specimen
Penetration tip size(mm) 10
Force (kg) 1.4
cu (kN/m2) 23.61
9 Detailed calculations can be found at Appendix VII.
23
5.5. Undrained Triaxial Test
5.5.1. Principles of Undrained Triaxial Test
In the undrained triaxial test, the cell pressure while load is added axially. The change in length
is measured to calculate the strain. The load is controlled and the instantaneous area is
calculated using the following equatio:
𝐴 =𝑉
𝑙=
𝐴0 (1 − 𝜀𝑣 )
(1 − 𝜀𝑎)
The deviatory stress is calculated using force over area and corrected using membrane
correction. The graph of deviatory stress against axial strain is plotted to find the deviatory
stress at failure.
24
5.5.2. Results of the Undrained Triaxial Test
The following diagrams show the result of the undrained triaxial tests conducted.
Fig. 5.1. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 100kPa)
STRAIN
DEV
ITOR
Y STRESS /kP
a
Maximum Deviatory Stress: 47.00kPa
25
Fig.5.2. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 150kPa)
Maximum Deviatory Stress: 52.65kPa
DEV
ITOR
Y STRESS /kP
a
STRAIN
26
Fig.5.3. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 200kPa)
Maximum Deviatory Stress: 41.89kPa
DEV
ITOR
Y STRESS /kP
a
27
Fig.5.4. Deviatory Stress Against Strain for Three Samples
DEV
ITOR
Y STRESS /kP
a
STRAIN
28
The deviatory stress at failure for the three samples can be seen in the following table.
Table 5.3. Deviatory Pressure at Failure
Sample Cell Pressure/kPa Deviatory Pressure/kPa
1 100 47.00
2 150 52.65
3 200 41.89
29
5.5.3. Mohr Circle and the Shear Strength
The Mohr Circles for the three samples are drawn and the failure envelopes are constructed to
obtain the shear strength.
Fig. 5.5. Mohr Circle and Failure Envelope for Triaxial Test
Table 5.4. Shear Strength of the Three Samples by Triaxial Test
Sample Cell Pressure/kPa Shear Strength / kPa
1 100 23.5
2 150 26.3
3 200 20.9
Average -- 23.6
30
5.6. Summary of Results for Three Samples
The following table summarizes the results for the three groups done on the same day. The
data calculated in this report is used as Specimen 1.10
Undrained shear strength, cu (kN/m2)
Specimen 1 Specimen 2 Specimen 3
Wood’s semi empirical eq 26,2 22.6 21.5
Lab. vane method
29.8 22.8 23.6
Pocket penetrometer 23.6 23.0 15.0
UU Triaxial test 23.6
10 Data for specimen 2 and 3 are taken directly from my friends in the other two groups.
31
5.7. Discussion
The results from Wood’s semi empirical equation is largely dependent on the accuracy of
Atterberg Test. Lab Vane Method and Pocket penetrometer are not very accurate as there is a
great uncertainty in handling the equiments. They can only be used as an estimation during site
investigation. The result from the triaxial test should be deemed as a more accurate value. Here
the result from the triaxial test is very close to the three estimations except for the lab vane
method. Thus, the result of the trialxial test is quite reliable but a ±3kPa of inaccuracy may be
included.
32
6. Assessment of Data
6.1. Correlation of Atterberg Limits Test and 1D Consolidation Test
The following relations have been proposed to correlate the two tests.
Table 6.1. Correlation of Atterberg Limits Test and cc Values
Relation Value of cc
𝑐𝑐 = 0.007(𝐿𝐿 − 10%) (Remoulded) 0.5649
𝑐𝑐 = 0.009(𝐿𝐿 − 10%) (Unremoulded) 0.7263
𝑐𝑐 = 0.01346 𝑃𝐼 0.7309
𝑐𝑐 = 0.02116(𝑃𝐿 − 9%) 0.5798
𝑐𝑐 = 0.009(𝐿𝐿 − 9%) 0.7353
𝑐𝑐 = 0.005 𝐺𝑠𝑃𝐼 0.7195
As the value of cc obtained from 1D Consolidation Test is 0.280, which is significantly smaller
than the results from above estimation, the 1D Consolidation Test does not correlate well with
the Atterberg Test results.
33
6.2. Correlation of Atterberg’s Limits Test and Tests for Undrained Shear Strength
As the cu value obtained from Wood’s Relation (26.2kPa) is close to the value from the triaxia l
test (23.6kPa), a strong correlation is observed.
34
6.3. Comparison with Existing Guidelines
6.3.1. Atterberg’s Limit Test
Low (2004)11 has suggested some values for Atterberg’s Limits and here is the comparisons.
Table 6.2. Comparisons of Atterberg’s Limit with Existing Parameters
Parameters Low’s Values Our Test Results
Plastic Limit(PL) 29±3% 36.4%
Liquid Limit(LL) 75±6% 90.7%
Although our results do not fall within the range, they are quite close to the upper bound of
Low’s recommended values and hence they can be deemed as consistent results.
11 H.E.Low, 2004, “ Compressibility and Undrained Behaviour of Natural Singapore Marine Clay: Effect of Soil Structure” Master T hesis
for Civil Engineering, NUS.
35
6.3.2. One Dimension Consolidation Test
Chu et al (2002)12 has suggested some values for 1D consolidation results and here is the
comparison.
Table 6.3. Comparisons of 1D Consolidations Results with Existing Parameters
Parameters Chu’s Recommendations Our Test Results
Coefficient of Volume
Change (cv) / m2year-1
Upper: 0.5 ~ 1.7
Lower: 0.5 ~ 2.3
Result 1: 8.88
Result 2: 3.08
Result 3: 0.83
Result 4: 0.79
Result 5: 1.68
Permeability (k) / ms-1 3x10-113x10-10 Result 1: 1.82x10-10
Result 2: 7.35x10-11
Result 3: 2.83x10-11
Result 4: 2.88x10-11
Result 5: 6.71x10-11
The upper bound of our cv value is a bit far off from Chu’s data. The value of 8.88 should be
rejected. Thus, the first value of k should also be rejected. The rest of the results for k values
fall within Chu’s recommendations.
12
J. Chu, Myint Win Bo, M. F. Chang, and V. Choa,2002 “Consolidation and Permeability Properties of Singapore Marine Clay” ASCE
Journal of Geotechnical & Geo-environmental Engineering ,Volume 128 Issue 9
36
7. Recommended Design Parameters
Table 7.1. Design Parameters
Parameters Values
Plastic Limit (PL) 36%
Liquid Limit (LL) 90%
Plasticity Index (PI) 54%
Soil Classification CH
Compression Index (Cc) 0.280
Swelling Index(Cs) 0.0325
Pre-Consolidation Pressure (Pc’) 186±10 kPa
Coefficient of Volume Change(mv) 6.0x10-5 ~ 1.2x10-4 m2/kN
Coefficient of Volume Change (cv) 0.8~3.0 m2/year
Permeability (k) 3x10-11 7x10-11
Undrained Shear Strength (cu) 23.6 ±3.0 kPa
37
APPENDICES
Appendix I: Test For Liquid Limit (cone penetrometer) and Plastic Limit – Based on
BS 1377-2:1990
Location
Job ref.
Borehole/Pit no.
Soil description
Singapore Marine Clay Sample no.
Depth m
Test Method BS
1377-2:1990 Date 10/02/2014
Plastic Limit
PLASTIC LIMIT Test no. 1 2 3 4 5 Average
Container no. g 1 2 3
Mass of wet soil + Container g 20.86 11.18 9.87
Mass of dry soil + Container g 20.57 10.72 9.5
Mass of container g 19.68 9.57 8.49
Mass of moisture g 0.29 0.46 0.37
Mass of dry soil g 0.89 1.15 1.01
Moisture content % 32.58% 40.00% 36.63% 36.41%
Liquid Limit
Test no. 1 2 3 4 5 6
Initial dial gauge reading/mm 0 0 0 0 0 0
Final dial gauge reading/mm 15.30 15.30 15.30 17.09 17.09 17.09
Average penetration/mm 15.30 17.09
Container no. 1 2 3 4 5 6
Mass of wet soil + cont./g 17.68 18.61 17.97 16.47 16.67 13.61
Mass of dry soil + cont./g 14.51 14.59 14.50 13.84 13.37 11.28
Mass of container/g 10.58 9.52 10.35 10.75 9.45 8.54
Mass of moisture/g 3.17 4.02 3.47 2.63 3.30 2.33
Mass of dry soil/g 3.93 5.07 4.15 3.09 3.92 2.74
Moisture content/% 80.66% 79.29% 83.61% 85.11% 84.18% 85.04%
Average moisture content % 81.19% 84.78%
Test no. 7 8 9 10 11 12
Initial dial gauge reading/mm 0 0 0 0 0 0
Final dial gauge reading/mm 21.70 21.70 21.70 21.85 21.85 21.85
Average penetration/mm 21.70 21.85
38
Container no. 7 8 9 10 11 12
Mass of wet soil + cont./g 17.92 23.92 17.56 19.29 20.44 22.84
Mass of dry soil + cont./g 13.81 16.99 13.73 14.50 15.13 16.49
Mass of container/g 9.47 9.63 9.66 9.45 9.57 9.64
Mass of moisture/g 4.11 6.93 3.83 4.79 5.31 6.35
Mass of dry soil/g 4.34 7.36 4.07 5.05 5.56 6.85
Moisture content/% 94.70% 94.16% 94.10% 94.85% 95.50% 92.70%
Average moisture content % 94.32% 94.35%
Sample preparation*
as received
washed on 425 m sieve
air dried at 25 oC oven dried at 105 oC
not known proportion retained
on 425 m sieve …… %
Liquid limit: 90.72%
Plastic limit: 36.41%
Plasticity index: 54.31%
*Delete as appropriate
Calculation for Liquid Limit:
𝑈𝑠𝑖𝑛𝑔 𝑦 = 49.186𝑥 − 24.623
When y = 20.0
𝑥 = 20.0 + 24.623
49.186
𝑥 = 0.907 = 90.72%
Thus, the Liquid Limit (LL) for the sample is 90.72%
y = 49.186x - 24.623
R² = 0.9997
12
14
16
18
20
22
24
80% 81% 82% 83% 84% 85% 86% 87% 88% 89% 90% 91% 92% 93%94%95%96%
Cone
Pe
netr
atio
n /m
m
Moisture Content %
Liquid Limit
39
Appendix II: Water Content/Bulk Density for Consolidation Test
WATER CONTENT/BULK DENSITY
Site: Natural/After Bore Hole:
Sample no: Consolidation / Direct Shear/ Vane Shear/ Triaxial Shear/Test
Specimen Test No: Date: 3/3/2014
1 2 3
Can No. A B C Dia of ring/soil cm 6.963
Can+ wet soil/gm 33.48 31.27 28.13
Height of ring/soil cm
1.858
Can+ dry
soil/gm 27.54 25.81 23.25 Ring + wet soil gm
206.76
Can only/gm 9.52 9.56 8.62 Ring only 74.46
Water/gm 5.94 5.46 4.88 Wet soil only gm 132.30
Dry soil/gm 18.02 16.25 14.63 Volume of soil cm3 70.75
Water Content/% 32.96% 33.60% 33.36%
Bulk density gm/cm3
1.87
WATER CONTENT/BULK DENSITY
Site: Natural/After Bore Hole: Sample no: Consolidation / Direct Shear/
Vane Shear/ Triaxial Shear/Test Specimen Test No: Date: 3/3/2014
1 2 3
Can No. A B C Dia of ring/soil cm
Can+ wet
soil/gm 18.15 18.89 14.90
Height of ring/soil
cm
Can+ dry soil/gm 16.26 16.88 13.73 Ring + wet soil gm
Can only/gm 9.65 9.53 9.73 Ring only
Water/gm 1.89 2.01 1.17 Wet soil only gm
Dry soil/gm 6.61 7.35 4.00 Volume of soil cm3
Water
Content/% 28.59% 27.35% 29.25%
Bulk density
gm/cm3
40
Table II.I Summary of the Key Data Before Consolidation
Gs 2.65
w(Water Content) 33.31%
Bulk Density 1.87
Sr(Degree of Saturation) 100%
e(Void Ratio) 0.883
Table II.II Summary of the Key Data After Consolidation
Gs 2.65
w(Water Content) 28.40%
Sr(Degree of Saturation) 100%
e(Void Ratio) 0.753
41
Appendix III: Calculations for Casagrande’s Method to Determine cs,cc and pc’
Legend
P Point of maximum Curvature
CD Straight Line Backward from Virgin Compression Curve
PR Tangent of the Curve at P
PQ Horizontal Line Intersects P
PS Bisector of Angle QPR
Fig. III.I Graph of Casagrande’s Method to Determine cs, cc and pv’
Logarithm of Effective Vertical Stress, log (σ’)/log(kPa)
Vo
id ratio
,e
42
Calculation:
𝑐𝑐 =0.800 − 0.744
2.61 − 2.41= 0.280
𝑐𝑠 = 0.757 − 0.744
2.45 − 2.05= 0.0325
𝑝𝑐′ = 102.27 = 186.2𝑘𝑃𝑎
43
Appendix IV: Graphs and Calculations for Casagrande’s log(time) Curve Fitting
Method
Fig. IV.I Graph of Settlement Against log(time) (20kg Load)
log(𝑡50) = 1.7
𝑡50 = 101.8 = 63.0957𝑠
𝐻 =𝐻0
2=
18.580
2= 9.290𝑚𝑚 = 9.290 × 10−3𝑚
𝑐𝑣 𝑡50
𝐻2= 𝑇 = 0.196
𝑐𝑣 = 0.196 × 𝐻2
𝑡50
= 0.196 × (9.290 × 10−3) 2
50.1187
𝑐𝑣 = 2.815 × 10−7 𝑚2𝑠−1 = 8.88 𝑚2𝑦𝑒𝑎𝑟−1
Log(time)/log(s)
H/m
m
44
Fig. IV.II Graph of Settlement Against log(time) (40kg Load)
log(𝑡50) = 2.235
𝑡50 = 102.235 = 171.79𝑠
𝐻 =𝐻0
2=
18.517
2= 9.2585𝑚𝑚 = 9.2585 × 10−3 𝑚
𝑐𝑣 𝑡50
𝐻2= 𝑇 = 0.196
𝑐𝑣 = 0.196 × 𝐻2
𝑡50
= 0.196 × (9.2585 × 10−3) 2
171.79
𝑐𝑣 = 9.780 × 10−8 𝑚2 𝑠−1 = 3.08 𝑚2𝑦𝑒𝑎𝑟−1
Log(time)/log(s)
H/m
m
45
Fig. IV.III Graph of Settlement Against log(time) (80kg Load)
log(𝑡50) = 2.800
𝑡50 = 102.800 = 630.9573𝑠
𝐻 =𝐻0
2=
18.372
2= 9.186𝑚𝑚 = 9.186 × 10−3𝑚
𝑐𝑣 𝑡50
𝐻2= 𝑇 = 0.196
𝑐𝑣 = 0.196 × 𝐻2
𝑡50
= 0.196 × (9.186 × 10−3 ) 2
630.9573
𝑐𝑣 = 2.621 × 10−8 𝑚2 𝑠−1 = 0.827 𝑚2𝑦𝑒𝑎𝑟−1
Log(time)/log(s)
H/m
m
46
Fig. IV.IV Graph of Settlement Against log(time) (160kg Load)
log(𝑡50) = 2.800
𝑡50 = 102.235 = 630.9573𝑠
𝐻 =𝐻0
2=
17.965
2= 8.9825𝑚𝑚 = 8.9825 × 10−3 𝑚
𝑐𝑣 𝑡50
𝐻2= 𝑇 = 0.196
𝑐𝑣 = 0.196 × 𝐻2
𝑡50
= 0.196 × (8.9825 × 10−3) 2
630.9573
𝑐𝑣 = 2.506 × 10−8 𝑚2 𝑠−1 = 0.790 𝑚2𝑦𝑒𝑎𝑟−1
Log(time)/log(s)
H/m
m
47
Fig. IV.V Graph of Settlement Against log(time) (40kg unload)
log(𝑡50) = 2.50
𝑡50 = 102.50 = 316.23𝑠
𝐻 =𝐻0
2=
17.138
2= 8.569𝑚𝑚 = 9.569 × 10−3𝑚
𝑐𝑣 𝑡50
𝐻2= 𝑇 = 0.196
𝑐𝑣 = 0.196 × 𝐻2
𝑡50
= 0.196 × (9.2585 × 10−3) 2
316.23
𝑐𝑣 = 5.313 × 10−8 𝑚2𝑠−1 = 1.68 𝑚2𝑦𝑒𝑎𝑟−1
Log(time)/log(s)
H/m
m
48
Appendix V: Water Content for Shear Strength Test
WATER CONTENT/BULK DENSITY
Site: Natural/After
Bore Hole: Sample no: Consolidation / Direct Shear/
Vane Shear/ Triaxial Shear/Test Specimen Test No: Date: 31/3/2014
1 2 3
Can No. A B C Dia of ring/soil cm
Can+ wet
soil/gm 16.726 19.002 15.728
Height of ring/soil
cm
Can+ dry soil/gm 14.143 15.492 13.446 Ring + wet soil gm
Can only/gm 9.755 9.56 9.471 Ring only
Water/gm 2.583 3.51 2.282 Wet soil only gm
Dry soil/gm 4.388 5.932 3.975 Volume of soil cm3
Water
Content/% 58.87% 59.17% 57.41%
Bulk density
gm/cm3
Average Water Content: 58.48%
49
Appendix VI: Calculations for Wood's Semi-Empirical Relation
Table. VI.I Key Parameters for Wood's Semi-empirical Relation
Natural Water Content (w) 58.48%
Plastic Limit(PL) 36.41%
Liquid Limit (LL) 90.72%
Plasticity Index(PI) 54.31%
Using 𝐿𝐼 = 𝑤−𝑃𝐿
𝑃𝐼
𝐿𝐼 =0.5848 − 0.3641
0.5431= 0.4064
Using 𝑐𝑢 = 170 × 𝑒−4.6 𝐿𝐼
𝑐𝑢 = 170 × 𝑒−4.6 ×0.4064 = 26.22 𝑘𝑁𝑚−2
Thus, the 𝑐𝑢 value from Wood's Semi-Empirical Relation is 26.22 𝑘𝑁𝑚−2.
50
Appendix VII: Calculations for Laboratory Vane Method
Table VII.I. Raw Data for Laboratory Vane Method
Vane No. A232 N2
Initial angle (degree) 252
Final angle(degree) 329
Angle of rotation(degree) 77
The overall width of the vane(m) 0.0127
The length of the vane(m) 0.0127
Table VII.II. Calibration Factors for Laboratory Vane Springs
Degrees of rotation (o) Torque
Spring No.2 Spring No.
(kg. cm) 2 (S/N. (S/N.2022)
A232)
0.25 15 15 0.50 30 30
0.75 45
1.00 59 60
1.25 74
1.50 89 91
1.75 105
2.00 120 121
2.25 134
2.50 148 151
2.75 163
3.00 177 181
51
Fig. VII.I. Calibration charts for laboratory vane shear test
Calculations:
Using 𝑦 = 0.0166𝑥
When angle of rotation is 77 degrees
Applied Torque 𝑀 = 0.0166 × 77 = 1.2782 𝑘𝑔 𝑐𝑚 = 1.2782 × 10−2𝑘𝑔𝑚
𝑐𝑢 = 𝑀
𝜋𝐷2(𝐻2
+𝐷6
)
𝑐𝑢 = 1.2782 × 10−2 × 10
𝜋 × 0.01272 × (0.0127
2+
0.01276
)
𝑐𝑢 = 29790 𝑁 𝑚−2
𝑐𝑢 = 29.79 𝑘𝑁 𝑚−2
Thus, the 𝑐𝑢 value from Laboratory Vane Method is 29.79 𝑘𝑁 𝑚−2 .
52
Table VII.III. Completed Data for Laboratory Vane Method
Specimen
Vane No A232 N2
Initial angle (o) 252
Final angle (o) 329
Angle of rotation (o) 77
cu (kN/m2) 29.79
53
Appendix VIII: Calculations Pocket Penetrometer Method
Table VIII.I. Raw Data for Pocket Penetrometer Method
Specimen
Penetration tip size(mm) 10
Force (kg) 1.4
Table VIII.II. Pocket Penetrometer Calibration Factors
54
Fig. VIII.I. Calibration chart for pocket penetrometer test
Fig. VIII.II. Calibration chart for pocket penetrometer test (10mm only)
55
56
Calculation
Using 𝑦 = 0.0593𝑥 + 0.0003
When Force = 1.4kg
Untrained Shear Stress 𝑐𝑢 = 1.4+0.0003
0.0593= 23.61 𝑘𝑃𝑎
Thus, the 𝑐𝑢 value from pocket penetrometer method test is 23.61 𝑘𝑁 𝑚−2 .
Table VIII.III. Completed Data for Pocket Penetrometer Method
Specimen
Penetration tip size(mm) 10
Force (kg) 1.4
cu (kN/m2) 23.61
57
Appendix IX: Data and Results for UU Triaxial Test Result and Analysis
Table IX.I. Result of Triaxial Test for Cell Pressure 100kPa
Comp Gauge(div)
Force Gauge(div)
Comp of Sample(mm)
Strain (%)
L=76mm
Corrected Area
A=(mm^2) D=38mm
Force P (kN)
Deviator Stress P/A
(kN/m^2)
Membrane Correction
Corrected Deviator Stresses
P/A (kN/m^2)
0 0 0 0.00% 1134.3 0.0000 0.000 0.000 0.000
50 21 0.5 0.66% 1141.7 0.0282 24.699 0.138 24.561
100 29 1 1.32% 1149.4 0.0389 33.880 0.239 33.641
150 34 1.5 1.97% 1157.1 0.0457 39.457 0.329 39.128
200 37 2 2.63% 1164.9 0.0497 42.651 0.412 42.239
250 38 2.5 3.29% 1172.8 0.0510 43.508 0.491 43.017
300 39 3 3.95% 1180.8 0.0524 44.351 0.567 43.784
400 42 4 5.26% 1197.3 0.0564 47.104 0.711 46.393
500 43 5 6.58% 1214.1 0.0577 47.558 0.848 46.711
600 44 6 7.89% 1231.5 0.0591 47.977 0.979 46.998
700 44 7 9.21% 1249.3 0.0591 47.293 1.105 46.188
800 45 8 10.53% 1267.7 0.0604 47.666 1.227 46.439
900 45 9 11.84% 1286.6 0.0604 46.966 1.346 45.619
1000 44 10 13.16% 1306.1 0.0591 45.236 1.463 43.773
1100 43 11 14.47% 1326.2 0.0577 43.538 1.577 41.961
1200 43.5 12 15.79% 1346.9 0.0584 43.368 1.689 41.679
1300 43.5 13 17.11% 1386.3 0.0584 42.135 1.799 40.336
1400 44 14 18.42% 1390.4 0.0591 42.494 1.907 40.587
1500 44 15 19.74% 1413.3 0.0591 41.805 2.013 39.792
58
Fig. IX.I. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 100kPa)
Maximum Deviatory Stress: 47.00kPa
STRAIN
DEV
ITOR
Y STRESS /kP
a
Maximum Deviatory Stress: 47.00kPa
59
Table IX.II. Result of Triaxial Test for Cell Pressure 150kPa
Comp Gauge(div)
Force Gauge(div)
Comp of Sample(mm)
Strain (%)
L=76mm
Corrected Area
A=(mm^2) D=38mm
Force P (kN)
Deviator Stress P/A
(kN/m^2)
Membrane Correction
Corrected Deviator Stresses
P/A (kN/m^2)
0 0 0 0.00% 1134.3 0.0000 0.000 0.000 0.000
50 44 0.5 0.66% 1141.7 0.0370 32.424 0.138 32.286
100 51 1 1.32% 1149.4 0.0429 37.331 0.239 37.092
150 57 1.5 1.97% 1157.1 0.0480 41.445 0.329 41.116
200 62 2 2.63% 1164.9 0.0522 44.778 0.412 44.366
250 65.5 2.5 3.29% 1172.8 0.0551 46.988 0.491 46.496
300 67.5 3 3.95% 1180.8 0.0568 48.094 0.567 47.527
400 70 4 5.26% 1197.3 0.0589 49.188 0.711 48.477
500 75 5 6.58% 1214.1 0.0631 51.972 0.848 51.125
600 78.5 6 7.89% 1231.5 0.0660 53.629 0.979 52.651
700 78.5 7 9.21% 1249.3 0.0660 52.865 1.105 51.760
800 79.5 8 10.53% 1267.7 0.0669 52.761 1.227 51.534
900 80.5 9 11.84% 1286.6 0.0677 52.640 1.346 51.294
1000 80 10 13.16% 1306.1 0.0673 51.532 1.463 50.069
1100 80 11 14.47% 1326.2 0.0673 50.751 1.577 49.174
1200 79 12 15.79% 1346.9 0.0665 49.347 1.689 47.658
1300 79 13 17.11% 1386.3 0.0665 47.944 1.799 46.146
1400 79 14 18.42% 1390.4 0.0665 47.803 1.907 45.896
1500 78.5 15 19.74% 1413.3 0.0660 46.731 2.013 44.718
60
Fig. IX.II. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 150kPa)
Maximum Deviatory Stress: 52.65kPa
Maximum Deviatory Stress: 52.65kPa
DEV
ITOR
Y STRESS /kP
a
STRAIN
61
Table IX.II. Result of Triaxial Test for Cell Pressure 200kPa
Comp Gauge(div)
Force Gauge(div)
Comp of Sample(mm)
Strain (%)
L=76mm
Corrected Area
A=(mm^2) D=38mm
Force P (kN)
Deviator Stress P/A
(kN/m^2)
Membrane Correction
Corrected Deviator Stresses
P/A (kN/m^2)
0 0 0 0.00% 1134.3 0.0000 0.000 0.000 0.000
50 18 0.5 0.66% 1141.7 0.0242 21.171 0.138 21.032
100 23 1 1.32% 1149.4 0.0309 26.870 0.239 26.631
150 27 1.5 1.97% 1157.1 0.0363 31.333 0.329 31.005
200 30.5 2 2.63% 1164.9 0.0410 35.158 0.412 34.746
250 31.5 2.5 3.29% 1172.8 0.0423 36.066 0.491 35.575
300 32.5 3 3.95% 1180.8 0.0436 36.959 0.567 36.392
400 34.5 4 5.26% 1197.3 0.0463 38.693 0.711 37.981
500 36.5 5 6.58% 1214.1 0.0490 40.369 0.848 39.522
600 38 6 7.89% 1231.5 0.0510 41.434 0.979 40.456
700 40 7 9.21% 1249.3 0.0537 42.994 1.105 41.889
800 40 8 10.53% 1267.7 0.0537 42.370 1.227 41.142
900 40 9 11.84% 1286.6 0.0537 41.747 1.346 40.401
1000 39.5 10 13.16% 1306.1 0.0530 40.610 1.463 39.147
1100 39.5 11 14.47% 1326.2 0.0530 39.994 1.577 38.417
1200 39 12 15.79% 1346.9 0.0524 38.881 1.689 37.193
1300 39 13 17.11% 1386.3 0.0524 37.776 1.799 35.978
1400 38.5 14 18.42% 1390.4 0.0517 37.182 1.907 35.275
1500 38 15 19.74% 1413.3 0.0510 36.104 2.013 34.091
62
Fig. IX.III. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 200kPa)
Maximum Deviatory Stress: 41.15kPa
Maximum Deviatory Stress: 41.89kPa
DEV
ITOR
Y STRESS /kP
a
STRAIN
63
Fig. IX.IV. Mohr Circle and Failure Envelope for Triaxial Test
Table.IX.IV. Failure Envelopes
Cell Pressure(kPa) Failure Envelope/kPa
100 23.5
150 26.3
200 20.9