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

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 2

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

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

-5 -4 2 Coefficient of Volume Change(mv) 6.0x10 ~ 1.2x10 m /kN

2 Coefficient of Volume Change (cv) 0.8~3.0 m /year

Permeability (k) 3x10-11 7x10-11

Undrained Shear Strength (cu) 23.6 ±3.0 kPa

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

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.

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. 7

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. 8

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.

Soil Sample

Fig. 3.1. Plasticity chart for laboratory classification of fine grained soil

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 liquidity 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.

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:

∆퐻 ∆푒 = 퐻 (1 + 푒)

The value of coefficient of volume changes 푚푣 can also be calculated using the following equation:

−∆푒 푚푣 = ∆휎푣′(1 + 푒)

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

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/H ∆e e 푚푣

(H)/mm /푘푃푎−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

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.

Void ratio,e

Logarithm of Effective Vertical Stress, log (σ’)/log(kPa)

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.

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 intersection gives the pre-consolidation pressure.

The results are summarized in the following table.3

Table 4.3. Values of cc, cs and pc’

Sample

푐푐 0.280

푐푠 0.0325

′ 푝푐 /kPa 186.2

3 Detailed calculation can be found at Appendix III. 14

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 푡50 . The value of coefficient of consolidation cv is calculated using the following equation:

푐 × 푡 푣 50 = 0.196 퐻2

Fig. 4.2. An Example of Casagrande’s log(time) Curve Fitting Method

4 Here is the value of 푐푣 obtained from this method.

Table 4.4. Values of cv

2 −1 2 −1 Day Load/kg 퐶푣/푚 푠 퐶푣/푚 푦푒푎푟

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. 16

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

−1 2 −1 2 −1 −15 Day 푚푣/푘푃푎 퐶푣/푚 푠 퐶푣/푚 푦푒푎푟 푘/푚푠

-10 1 6.478×10-5 2.815×10-8 8.88 1.824×10

-11 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

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 equation푘 = 푐푣 푚푣훾푤. 17

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. 18

5. Shear Strength Test

5.1. Principles

In the experiment, four different tests are conducted to evaluate the shear strength.

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:

−4.6 퐿퐼 푐푢 = 170 × 푒

Where LI is the liquidity index given by:

푤 − 푃퐿 퐿퐼 = 푃퐼

Where w is the water content

PL is the plastic limit and

PI is the plasticity index.

Using the Atterberg Limits obtained above, the 푐푢 value from Wood's Semi-Empirical Relation is 26.22 푘푁푚−2 .7

7 Detailed calculations can be found in Appendix IV. 20

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:

푀 푐푢 = 2 퐻 퐷 휋퐷 (2 + 6 )

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

2 cu (kN/m ) 29.79

8 For the detailed calculation of the results, please refer to Appendix VII. 21

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 푐푢 and the value

9 of 푐푢 can be read from the pre-calibrated graph. The result of the test is summarized below.

Table 5.2. Data for Pocket Penetrometer Method

Specimen

Penetration tip size(mm) 10

Force (kg) 1.4

2 cu (kN/m ) 23.61

9 Detailed calculations can be found at Appendix VII.

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:

푉 퐴 (1 − 휀 ) 퐴 = = 0 푣 푙 (1 − 휀푎)

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.

5.5.2. Results of the Undrained Triaxial Test

The following diagrams show the result of the undrained triaxial tests conducted.

Maximum Deviatory Stress: 47.00kPa

DEVITORY STRESS /kPa

STRAIN

Fig. 5.1. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 100kPa)

Maximum Deviatory Stress: 52.65kPa

DEVITORY STRESS /kPa

STRAIN Fig.5.2. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 150kPa)

Maximum Deviatory Stress: 41.89kPa

DEVITORY STRESS /kPa

Fig.5.3. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 200kPa)

DEVITORY STRESS /kPa

STRAIN

Fig.5.4. Deviatory Stress Against Strain for Three Samples

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

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

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

2 Undrained shear strength, cu (kN/m )

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.

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.

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

푐푐 = 0.007(퐿퐿 − 10%) (Remoulded) 0.5649

푐푐 = 0.009(퐿퐿 − 10%) (Unremoulded) 0.7263

푐푐 = 0.01346 푃퐼 0.7309

푐푐 = 0.02116(푃퐿 − 9%) 0.5798

푐푐 = 0.009(퐿퐿 − 9%) 0.7353

푐푐 = 0.005 퐺푠푃퐼 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.

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 triaxial test (23.6kPa), a strong correlation is observed.

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.

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 Upper: 0.5 ~ 1.7 Result 1: 8.88

2 -1 Change (cv) / m year Lower: 0.5 ~ 2.3 Result 2: 3.08

Result 3: 0.83

Result 4: 0.79

Result 5: 1.68

Permeability (k) / ms-1 3x10-113x10-10 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

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

-5 -4 2 Coefficient of Volume Change(mv) 6.0x10 ~ 1.2x10 m /kN

2 Coefficient of Volume Change (cv) 0.8~3.0 m /year

Permeability (k) 3x10-11 7x10-11

Undrained Shear Strength (cu) 23.6 ±3.0 kPa

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 Sample no. Singapore Marine Clay Depth m Test Method BS Date 10/02/2014 1377-2:1990

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

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* Liquid Limit 24 as received washed on 425 m sieve 22 air dried at 25 oC oven dried at 105 oC 20 not known proportion retained 18 on 425 m sieve …… % 16 y = 49.186x - 24.623 Liquid limit: 90.72% R² = 0.9997 Cone Penetration Cone /mmPenetration Plastic limit: 36.41% 14

12 Plasticity index: 54.31% 80%81%82%83%84%85%86%87%88%89%90%91%92%93%94%95%96% Moisture Content % *Delete as appropriate

Calculation for Liquid Limit:

푈푠푖푛푔 푦 = 49.186푥 − 24.623

When y = 20.0

20.0 + 24.623 푥 = 49.186

푥 = 0.907 = 90.72%

Thus, the Liquid Limit (LL) for the sample is 90.72%

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 Height of ring/soil soil/gm 33.48 31.27 28.13 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 Bulk density Content/% 32.96% 33.60% 33.36% 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 Height of ring/soil soil/gm 18.15 18.89 14.90 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 Bulk density Content/% 28.59% 27.35% 29.25% gm/cm3

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

’ Appendix III: Calculations for Casagrande’s Method to Determine cs,cc and pc

Void ratio,e

Logarithm of Effective Vertical Stress, log (σ’)/log(kPa) 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’

Calculation:

0.800 − 0.744 푐 = = 0.280 푐 2.61 − 2.41

0.757 − 0.744 푐 = = 0.0325 푠 2.45 − 2.05

′ 2.27 푝푐 = 10 = 186.2푘푃푎

Appendix IV: Graphs and Calculations for Casagrande’s log(time) Curve Fitting

Method

Log(time)/log(s)

H/mm

Fig. IV.I Graph of Settlement Against log(time) (20kg Load)

log(푡50) = 1.7 1.8 푡50 = 10 = 63.0957푠 퐻 18.580 퐻 = 0 = = 9.290푚푚 = 9.290 × 10−3푚 2 2 푐 푡 푣 50 = 푇 = 0.196 퐻2 0.196 × 퐻2 0.196 × (9.290 × 10−3) 2 푐푣 = = 푡50 50.1187

−7 2 −1 2 −1 푐푣 = 2.815 × 10 푚 푠 = 8.88 푚 푦푒푎푟

Log(time)/log(s)

H/mm

Fig. IV.II Graph of Settlement Against log(time) (40kg Load)

log(푡50) = 2.235

2.235 푡50 = 10 = 171.79푠 퐻 18.517 퐻 = 0 = = 9.2585푚푚 = 9.2585 × 10−3 푚 2 2 푐 푡 푣 50 = 푇 = 0.196 퐻2 0.196 × 퐻2 0.196 × (9.2585 × 10−3) 2 푐푣 = = 푡50 171.79

−8 2 −1 2 −1 푐푣 = 9.780 × 10 푚 푠 = 3.08 푚 푦푒푎푟

Log(time)/log(s)

H/mm

Fig. IV.III Graph of Settlement Against log(time) (80kg Load)

log(푡50) = 2.800

2.800 푡50 = 10 = 630.9573푠 퐻 18.372 퐻 = 0 = = 9.186푚푚 = 9.186 × 10−3푚 2 2 푐 푡 푣 50 = 푇 = 0.196 퐻2 0.196 × 퐻2 0.196 × (9.186 × 10−3 ) 2 푐푣 = = 푡50 630.9573 −8 2 −1 2 −1 푐푣 = 2.621 × 10 푚 푠 = 0.827 푚 푦푒푎푟

Log(time)/log(s)

H/mm

Fig. IV.IV Graph of Settlement Against log(time) (160kg Load)

log(푡50) = 2.800 2.235 푡50 = 10 = 630.9573푠 퐻 17.965 퐻 = 0 = = 8.9825푚푚 = 8.9825 × 10−3 푚 2 2 푐 푡 푣 50 = 푇 = 0.196 퐻2 0.196 × 퐻2 0.196 × (8.9825 × 10−3) 2 푐푣 = = 푡50 630.9573 −8 2 −1 2 −1 푐푣 = 2.506 × 10 푚 푠 = 0.790 푚 푦푒푎푟

Log(time)/log(s)

H/mm

Fig. IV.V Graph of Settlement Against log(time) (40kg unload)

log(푡50) = 2.50

2.50 푡50 = 10 = 316.23푠 퐻 17.138 퐻 = 0 = = 8.569푚푚 = 9.569 × 10−3푚 2 2 푐 푡 푣 50 = 푇 = 0.196 퐻2 0.196 × 퐻2 0.196 × (9.2585 × 10−3) 2 푐푣 = = 푡50 316.23

−8 2 −1 2 −1 푐푣 = 5.313 × 10 푚 푠 = 1.68 푚 푦푒푎푟

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 Height of ring/soil soil/gm 16.726 19.002 15.728 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 Bulk density Content/% 58.87% 59.17% 57.41% gm/cm3

Average Water Content: 58.48%

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 퐿퐼 = 푤−푃퐿 푃퐼

0.5848 − 0.3641 퐿퐼 = = 0.4064 0.5431

−4.6 퐿퐼 Using 푐푢 = 170 × 푒

−4.6 ×0.4064 −2 푐푢 = 170 × 푒 = 26.22 푘푁푚

−2 Thus, the 푐푢 value from Wood's Semi-Empirical Relation is 26.22 푘푁푚 .

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. Spring No.2 (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

Fig. VII.I. Calibration charts for laboratory vane shear test

Calculations:

Using 푦 = 0.0166푥

When angle of rotation is 77 degrees

Applied Torque 푀 = 0.0166 × 77 = 1.2782 푘푔 푐푚 = 1.2782 × 10−2푘푔푚

푀 푐 = 푢 퐻 퐷 휋퐷2( + ) 2 6

1.2782 × 10−2 × 10 푐 = 푢 0.0127 0.0127 휋 × 0.01272 × ( + ) 2 6

−2 푐푢 = 29790 푁 푚

−2 푐푢 = 29.79 푘푁 푚

−2 Thus, the 푐푢 value from Laboratory Vane Method is 29.79 푘푁 푚 .

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

2 cu (kN/m ) 29.79

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

Fig. VIII.I. Calibration chart for pocket penetrometer test

Fig. VIII.II. Calibration chart for pocket penetrometer test (10mm only)

Calculation

Using 푦 = 0.0593푥 + 0.0003

When Force = 1.4kg

Untrained Shear Stress 푐 = 1.4+0.0003 = 23.61 푘푃푎 푢 0.0593

−2 Thus, the 푐푢 value from pocket penetrometer method test is 23.61 푘푁 푚 .

Table VIII.III. Completed Data for Pocket Penetrometer Method

Specimen

Penetration tip size(mm) 10

Force (kg) 1.4

2 cu (kN/m ) 23.61

Appendix IX: Data and Results for UU Triaxial Test Result and Analysis Table IX.I. Result of Triaxial Test for Cell Pressure 100kPa

Corrected Corrected Deviator Strain Deviator Comp Force Comp of Area Force Stress Membrane (%) Stresses Gauge(div) Gauge(div) Sample(mm) A=(mm^2) P (kN) P/A Correction L=76mm P/A D=38mm (kN/m^2) (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

Maximum Deviatory Stress: 47.00kPa

DEVITORY STRESS /kPa

STRAIN

Fig. IX.I. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 100kPa)

Maximum Deviatory Stress: 47.00kPa

Table IX.II. Result of Triaxial Test for Cell Pressure 150kPa

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

Maximum Deviatory Stress: 52.65kPa

DEVITORY STRESS /kPa

STRAIN

Fig. IX.II. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 150kPa)

Maximum Deviatory Stress: 52.65kPa

Table IX.II. Result of Triaxial Test for Cell Pressure 200kPa

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

Maximum Deviatory Stress: 41.89kPa

DEVITORY STRESS /kPa

Fig. IX.III. Deviatory Stress Against Strain for Triaxial Test (Cell Pressure 200kPa)

STRAIN Maximum Deviatory Stress: 41.15kPa

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