1 rnnnrn1 - Universiti Malaysia Pahang

1 rnnnrn1 STRENGTH AND 0 0000086937 L REINFORCED WITH

BOTTOM ASH COLUMNS

MUZAMIR BIN HASAN

A thesis submitted in fulfillment of the

requirements for the award of the degree of

Doctor of Philosophy (Civil Engineering)

Faculty of Civil Engineering

Universiti Teknologi Malaysia

DECEMBER 2013

' , ~

I ~

l1/ll ll4 PERPUSTAKA UN AN IVERSITI MALAYSIA PAHANG

lJ8erolehan No. Panggllan 6831 iA

Tarikh Ge:,o . a;

~ 1 JUL 2014 . M'is'~ '.l.01J

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v

ABSTRACT

Stone column could be used as a ground improvement technique where a portion of the soft soil is replaced with granular material such as crushed rocks or sand which is proven to increase bearing capacity and accelerate the dissipation of excess pore water pressure. This research was aimed to investigate the role of bottom ash columns in improving the shear strength and compressibility of soft reconstituted kaolin clay. This was done by determining the effects of area replacement ratio, height penetrating ratio and volume replacement ratio of a single and a group of bottom ash columns on the strength characteristics and also the effects of confining pressure on the compressibility characteristics of kaolin clay reinforced with bottom ash column(s). Among the objectives of this research include establishing a design chart that correlating the undrained shear strength of bottom ash column(s) reinforced kaolin clay with the volume replacement ratio and the mean normal effective stress, through critical state soil mechanics framework. The reinforced kaolin samples were subjected to using Unconfined Compression Test (UCT) and Consolidated Undrained (CU) Triaxial Test. Research variables include diameter and height of the bottom ash columns and effective confining pressure, 0"3 (also equals to mean normal effective stress, p' 0 ) . Analysis of the results had been carried out using the Mohr-Coulomb and critical state failure criteria. Based the results of UCT, it can be concluded that the undrained shear strength generally increased with the increased in the height penetrating ratio but decreased after reaching an optimum improvement at 80 % of height penetrating ratio. The increment of undrained shear strength was also dependent on the area replacement ratio. Without confining pressure, the higher the area replacement ratio, the higher the strength occurred. However, excessive area of replacement decreased the shear strength of the sample reinforced by group columns since the remaining width of the soil sample was too thin to hold the columns. Based on the Mohr-Coulomb failure criteria of the CU test results, the installation of bottom ash columns did not show any significant difference in the effective friction angle. However, it did result in an increase in the apparent cohesion and undrained shear strength of the kaolin clay. It is also proven that the dissipation of pore water pressure was accelerated with the presence of bottom ash columns. Analysis through the critical state soil mechanics framework revealed critical state parameters of M, r and /..., for each samples. Most of the M values for the soil-bottom ash composite lie between 1.25 and 1.33, giving a variation on the friction angle at critical state between 31° to 33°, hence fall under the "mixtures of gravel and sand with fine-grained soils" category. Generally it can be concluded that the shear strength and compressibility of soft clay could be improved by the installation of bottom ash columns. Hence, a design chart was established intended to become a design tool, particularly in the determining the volume of bottom ash needed to form the vertical columns achieve to the required shear strength of the improved clay soil.

Vl

ABSTRAK

Tiang batu boleh digunakan sebagai teknik pembaikan tanah yang mana sebahagian tanah lembut digantikan dengan bahan berbijian seperti batuan hancur atau pasir yang terbukti boleh meningkatkan keupayaan galas dan mempercepatkan pelesapan lebihan tekanan air liang. Penyelidikan ini bertujuan untuk mengkaji peranan tiang abu dasar dalam memperbaiki kekuatan ricih dan kebolehmampatan tanah liat kaolin lembut yang disusun semula. Ini dilakukan dengan menentukan kesan nisbah penggantian luas, nisbah ketinggian tertusuk dan nisbah penggantian isipadu bagi tiang abu dasar tunggal dan kumpulan selain kesan tekanan mengurung ke atas ciri-ciri kebolehmampatan tanah liat kaolin yang diperkukuh dengan tiang abu dasar. Antara objektif penyelidikan ini termasuk menwujudkan carta rekabentuk yang menghubungkan kekuatan ricih tak tersalir tanah liat kaolin yang diperkukuh dengan tiang abu dasar dengan nisbah penggantian isipadu dan purata tegasan normal berkesan, melalui kerangka kerja mekanik tanah keadaan genting. Sampel kaolin yang terkukuh dengan tiang abu dasar telah diuji menggunakan kaedah Ujikaji Mampatan Tak Terkurung (UCT) dan Ujikaji Tiga Paksi Terkukuh Tak Tersalir (CU). Pembolehubah kajian termasuk garis pusat dan ketinggian tiang abu dasar dan tekanan mengurung berkesan, a' 3 (yang juga bersamaan dengan purata tegasan berkesan normal, p' 0). Keputusan telah dilakukan menggunakan kriteria-kriteria kegagalan Mohr-Coulomb dan keadaan genting. Berdasarkan keputusan UCT, boleh disimpulkan bahawa secara arnnya kekuatan ricih tak tersalir meningkat dengan pertambahan nisbah tusukan ketinggian berkurang selepas mencapai pembaikan optimum pada 80 % nisbah tusukan ketinggian. Penambahan kekuatan ricih tak tersalir juga bergantung kepada nisbah penggantian luas. Tanpa tekanan mengurung, semakin tinggi nisbah penggantian luas, semakin tinggi kekuatan yang berlaku. Walau bagaimanapun, penggantian luas berlebihan menyebabkan kekuatan ricih tanah berkurangan bagi sampel tanah yang diperkukuhkan dengan tiang berkumpulan disebabkan lebar sampel tanah yang tinggal akan menjadi terlalu nipis untuk memegang tiang. Melalui kriteria kegagalan Mohr-Coulomb menggunakan keputusan ujikaji CU, pemasangan tiang abu dasar tidak menunjukkan perubahan besar dalam sudut geseran berkesan. Namun, ia menunjukkan peningkatan dalam lekatan nyata dan kekuatan ricih tak tersalir bagi tanah liat kaolin. Ianya juga terbukti bahawa pelesapan lebihan tekanan air liang dipercepatkan dengan kehadiran tiang abu dasar. Analisis melalui kerangka kerja mekanik tanah keadaan kritikal memperkenalkan parameter keadaan kritikal M, r dan A. untuk setiap sampel. Kebanyakan nilai M bagi komposit tanah-abu dasar adalah di antara 1.25 dan 1.33, memberikan variasi sudut geseran pada keadaan kritikal di antara 31° hingga 33°, menjadikannya termasuk di dalam kategori "campuran kerikil dan pasir dengan tanah butiran halus". Umumnya, kuatan ricih dan kebolehmampatan bagi tanah liat boleh bertambah baik oleh pemasangan tiang abu dasar. Satu carta rekabentuk telah dihasilkan bertujuan untuk menjadi panduan untuk proses rekabentuk, terutamanya dalam menentukan isipadu abu dasar yang diperlukan untuk menghasilkan tiang tegak, bagi mencapai kekuatan ricih yang diperlukan untuk menambah baik tanah liat.

vii

TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION 11

DEDICATION 111

ACKNOWLEDGEMENT lV

ABSTRACT v

ABSTRAK VI

CONTENTS Vll

LIST OF TABLES Xlll

LIST OF FIGURES xv

LIST OF APPENDICES xxv

LIST OF ABBREVIATIONS XXVl

LIST OF SYMBOLS XXVll

1 INTRODUCTION 1

1.1 Background of Research 1

1.2 Problem Statement 4

1.3 Objectives 5

1.4 Significance of Research 6

1.5 Scope of Research 7

1.6 Limitation of Research 9

1.7 Thesis Organization 10

2 LITERATURE REVIEW 13

2.1 Introduction 13

2.2 Sustainable Construction 13

Vlll

2.3 Soft Clay 16

2.3.1 Compressibility and Consolidation 18

2.3.2 Undrained Shear Strength 21

2.4 Critical State Theory 22

2.4.1 Definition of State Parameters 22

2.4.2 State Boundary Surface 24

2.4.3 Critical Voids Ratio Line 27


2.4.5 Critical State Parameters of Some Types of Soil 28

2.5 Bottom Ash 31

2.5.1 Bottom Ash Utilization 35

2.5.2 Physical and Mechanical Properties of Bottom Ash 3 7

2.5.2.1 Particle Size Distribution 37

2.5.2.2 Compaction 40

2.5.2.3 Specific Gravity 43

2.5.2.4 Permeability 45

2.5.2.5 Shear Strength 46

2.5.3 Morphological Characteristic 48

2.6 Ground Improvement 52

2.7 Stone Column 54

2.8 Small Scale Modelling on Stone Columns 57

2.8.1 General Physical Modeling Work 57

2.8.2 Preparation of Reconstituted Soft Clay 66

2.8.3 Column Installation Method 68

2.8.4 Shear Strength of Reinforced Clay 70

2.8.5 Consolidation around Vertical Granular Column 73

2.8.6 Critical Column Length 74

3 METHODOLOGY 76

3.1 Introduction 76

3.2 Selection of Ground Improvement Technique 78

3.3 Selection of Materials 78

3.4 Sample Collection 79

3.5 Determination of Basic, Mechanical and Chemical

ix

Properties of Materials 79

3.5.1 Sieve Analysis 81

3.5.2 Hydrometer 82

3.5.3 Specific Gravity 82

3.5.4 Atterberg Limits 83

3.5.5 Compaction Test 84

3.5.6 Relative Density 85

3.5.7 Permeability 86

3.5.8 Scanning Electron Microscope (SEM) 86

3.5.9 Vane Shear Test 87

3.5.10 Unconfined Compression Test (UCT) 88

3.5.11 Consolidated Undrained (CU) Triaxial Test 89

3.6 Design of Bottom Ash Column Model 91

3.6.1 General 91

3.6.2 Sample Preparation 92

3.6.2.1 Bottom Ash Sample 95

3.6.2.2 Kaolin Clay Samples 97

3.6.3 Bottom Ash Columns Installation 100

3.6.4 Bottom Ash Column Arrangement 102

3.7 Geotechnical Digital System (GDS) Fully Automated

Consolidated Undrained Triaxial Test 104

3.7.1 System Elements 107

3.7.2 CU Triaxial Test 109

3.7.2.1Stage1and2: Saturation Ramp 110

3.7.2.2 Stage 3: Saturation Check 112

3.7.2.3 Stage 4: Isotropic Consolidation 114

3.7.2.4 Stage 5: Shearing 115

3.7.2.5 Rate of Strain and Displacement 116

3.8 Data Analysis and Result Presentation 118

4 PROPERTIES OF RESEARCH MATERIALS 119

4.1 Introduction 119

4.2 Basic Properties 120

4.2.1 Particle Size Distribution 122

x

4.2.2 Atterberg Limit 123

4.2.3 Relative Density 124

4.2.3 Specific Gravity 125

4.3 Mechanical Properties 126

4.3.1 Compaction 126

4.3.2 Permeability 128

4.3.3 Shear Strength 129

4.3.3.l Direct Shear Test 129

4.3.3.2 Unconfined Compression Test 130

4.3.3 .2 Laboratory Vane Shear Test 131

4.3.3.3 Consolidated Undrained Triaxial Test 134

4.4 Morphological Properties 140

5 COMPRESSIBILITY 142


5.2 Consolidation Parameters 142

5.3 Controlled Sample 144

5.4 Samples Reinforced with Single Bottom Ash Column 146

5.4.l Height Penetrating Ratio, HJHs = 0.6 146

5.4.2 Height Penetrating Ratio, HJHs = 0.8 150


5.5 Samples Reinforced with Group of Bottom Ash Columns 157




5.6 Summary 168

6 SHEAR STRENGTH ANALYSIS 173


6.2 Unconfined Compression Test 173


6.2.2 The Effect of Area Replacement Ratio 177

6.2.3 Effect of Column Penetration Ratio 180

xi

6.2.4 Effects of Volume Replacement Ratio 183

6.3 Consolidated Undrained Triaxial Test 185

6.3.l Stress Strain Behavior 187

6.3.1.1 Single Columns 187

6.3.1.2 Group Colwnns 193

6.3.2 Excess Pore Pressure 198

6.3.3 Shear Strength Parameters 199

7 CRITICAL STATE ANALYSIS 207


7.2 Stresses and Void Ratio at Critical State 208

7.3 Controlled Sample 211

7.4 Samples Reinforced with Bottom Ash Column 214

7.4.1 Single Column 214

7.4.1.1 Height Penetrating Ratio, HcfHs = 0.6 216

7.4.1.2 Height Penetrating Ratio, HJHs = 0.8 220


7.4.2 Group Colwnns 228




7.5 Critical State Line Equations and Critical State

Parameters 242

7.6 Variation of M, A. and r with Volume Replacement

Ratio 245

7.7 Undrained Shear Strength at Critical State 246

7.7.l Theoretical Correlation of Undrained Shear

Strength with Specific Volume at Critical State 248

7.7.2 Variation of Undrained Shear Strength with

Specific Volume 252

7.7.3 Effect of Volume Replacement Ratio 256

7.8 Summary of Critical State Analysis 263

8 CONCLUSION AND RECOMMENDATIONS

8.1 Introduction

8.2 Conclusion

8.3 Contributions of Research

8.3.1 Ground Improvement

8.3.2 Sustainability

8.3.3 Economy

8.3.4 Originality

8.4 Recommendations for Future Research

REFERENCES

Appendices A-H

Xll

265

265

265

268

268

269

269

270

270

272

280 - 349

xiii

LIST OF TABLES

TABLE NO. TITLE PAGE

2.1 Comparison of index properties of clay in different places

(Mohd Amin et al., 1997) 18

2.2 Lightly overconsolidated clays and silts tested in USA

(GE05 user's guide, 2010) 20

2.3 Typical value of compression index of different type of soil

(GE05 user's guide, 2010) 20

2.4 Undrained strength classification of clay (Craig, 1983) 21

2.5 Critical state parameters of some soil types (Marto, 1996) 30

2.6 List of coal-fired plants in Malaysia (Wikipedia, 2012) 32

2.7 Current and forecast ash production ofTanjung Bin Power

Plant (Worley Parsons Resources and Energy, 2011) 33

2.8 Inventory of on-site disposal of ash at Tanjung Bin Power

Plant (Worley Parsons Resources and Energy, 2011) 33

2.9 Particle classification (Head, 1992) 38

2.10 Optimum moisture content and maximum dry density of

bottom ash from compaction tests 42

2.11 Results of specific gravity of bottom ash from previous works 44

2.12 Results of permeability of bottom ash from previous works 45

2.1 3 Results of direct shear test for bottom ash from previous works 47

2.14 Ranges of friction angles for soils (Budhu, 2007) 47

2.15 Effect of area replacement ratio on undrained shear strength

of reinforced clay 71

3.1 Tests and standards/methods for the main materials 80

3.2 Sample coding and testing programme of CU triaxial tests for

XlV

unreinforced clay and clay reinforced with bottom ash columns 91

3.3 Moisture content for kaolin specimens 99

3.4 Density of various dimensions of bottom ash columns

installed in kaolin specimens 101

4.1 Basic properties ofTanjung Bin bottom ash and kaolin 121

4.2 Comparison on the specific gravity of bottom ash from

coal-fired power plants in Malaysia 126

4.3 Statistical analysis on shear strength data from vane shear tests 132

4.4 Result of undrained shear strength from vane shear test 133

5.1 Consolidation parameters 143

6.1 Results from Unconfined Compression test 174

6.2 Peak deviator stress and axial strain from UCT 177

6.3 Effect of area replacement ratio for fully penetrating columns

on undrained shear strength 178

6.4 Summary results from consolidated undrained triaxial test 186

7.1 Deviator stress, mean normal effective stress and void ratio at

critical state 209

7.2 CSL equations and CS parameters from CU tests for kaolin

reinforced with bottom ash columns 244

7.3 Undrained shear strength and increased in the strength at critical

state 247

7.4 Calculated and laboratory values of undrained shear strengths,

and specific volumes of samples at critical states 249

7.5 Undrained shear strength at critical state and the corresponding

initial specific volume 253

xv

LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.1 Location of coal-fired power plants in Malaysia

(Mahmud, 2003) 2

2.1 The diagram of sustainability in construction

(Zainul Abidin, 2009) 15

2.2 Quaternary sediment in Peninsular Malaysia

(after Stauffer, 1973) 17

2.3 Critical state line and stress paths for undrained loading

on normally consolidated clay (Whitlow, 2001) 23

2.4 Plots oftriaxial tests results of CU and CD (Whitlow, 2001)

in: (a) q: p' space, (b) v: p' space 25

2.5 The critical state boundary surface (Whitlow, 2001) 26

2.6 United States of America electric power industry net

generation (U.S. Energy Information Administration, 2008) 34

2.7 Bottom ash applications as a percentage of total reused

(American Coal Ash Association, 2006) 37

2.8 Grain size distribution for fly and bottom ash from Tanjung

Bin Power Plant (Lee, 2008) 39

2.9 Grain size distribution curves of several bottom ash samples

(Recycled Materials Resource Centre, 2012) 40

2.10 Typical compaction curve for cohesionless soil

(Huang, 1990) 41

2.11 SEM photomicrographs of Tanjung Bin bottom ash

(Muhardi et al., 2010) 48

2.12 SEM photomicrographs of Tanjung Bin bottom ash

XVI

(Awang et al., 2011) 49

2.13 Particle shape of the bottom ash (Chen et al. , 2008) 49

2.14 Particle shape of the (a) bottom ash and (b) natural sand

(Bai and Basheer, 2002) 50

2.15 SEM of bottom ash (Won et al., 2004) 51

2.16 SEM of as-received bottom ash and ground bottom ash

(a) As-received bottom ash and (b) Ground bottom ash

(Sathonsaowaphak et al., 2009) 52

2.17 The installation of stone column in construction field

(McCabe et al., 2007) 56

2.18 Geogrid encased sand column in unconfined compression

test (Gniel and Bouazza, 2008) 59

2.19 Modified triaxial cell for testing reinforced soil specimen

(Juran and Riccobono, 1991) 60

2.20 Photographs of deformed sand columns exhumed at the end

of footing penetration (Muir Wood et al., 2010) 62

2.21 Loading patten and column arrangement (Black et al., 2007) 63

2.22 The sand columns installed in transparent 'claylike'

material (McKelvey, 2004) 65

2.23 Consolidation of kaolin samples (Hu, 1995) 67

2.24 Customized 1-D Consolidometers to generate homogenous

kaolin samples (Najjar et al., 2010) 68

2.25 The preparation for pre-drilled hole for the insertion of

granular column (Najjar et al., 2010) 69

2.26 Insertion of "frozen" granular column in clay specimen

(Najjar et al, 2010) 70

2.27 Deviator stress at failure for various column penetration ratios

(Black ei al., 2007) 72

2.28 Effect ofratio of column height to diameter (Najjar et al., 2010) 73

3.1 Flow chart for research methodology process 77

3.2 Scanning Electron Microscope model ZEISS EVO 87

3.3 Laboratory Vane Shear Test 88

3.4 Unconfined Compression Test on kaolin 89

3.5 Bottom ash being prepared for CU triaxial test 93

xvn

3.6 Bottom ash specimen during consolidation stage in CU triaxial

test 93

3.7 Bottom ash specimen during shearing stage in CU triaxial test 94

3.8 Apparatus for the preparation of soft homogenous kaolin

specimens 95

3.9 Kaolin mixed with water poured into the mould 95

3.10 Customized mould set for 50 mm diameter and 100 mm

height specimen 96

3.11 Kaolin compacted by pressing it from both ends by the

customized cap 96

3.12 Hole was drilled using 10 and 16 mm diameter drill bits 97

3.13 Specimens extruded out of the mould and kept inside the case 98

3.14 Location of points for moisture content determination 100

3.15 Installation of bottom ash in soft kaolin clay specimen 101

3.16 Detail column arrangement for single and group bottom ash

columns installed in clay specimens 103

3.17 Single and group bottom ash columns completely installed in

the soft kaolin clay specimen 104

3.18 GDS Fully Automated Triaxial System equipment setup 105

3.19 Diagram of GDSTAS Hardware elements

(GDS Instruments, 2010) 107

3.20 Advanced PressureN olume Controller for controlling of cell

pressure and back pressure 108

3.21 GDSLAB software 109

3.22 GDSLAB test plan for consolidated undrained triaxial test 110

3.23 Setup for Stage 1 111

3.24 Optional test termination conditions for Stage 1 112


3.26 Optional test termination condition for Stage 3 113


3.28 Optional test termination condition for Stage 4 115


3.30 Optional test start condition for Stage 5 118

4.1 Bottom ash obtained from Tanjung Bin coal-fired power plant 120

xviii

4.2 Particle size distribution of bottom ash and kaolin 123

4.3 The location of kaolin S300 in the plasticity chart (ASTM D2487) 124

4.4 Relationship between dry density and moisture content from

standard proctor compaction test for kaolin 127

4.5 Relationship between dry density and moisture content from

standard proctor compaction test for bottom ash 128

4.6 Graph of shear stress versus normal stress 130

4.7 Deviator stress and excess pore-water pressure versus axial

strain for kaolin clay and bottom ash 135

4.8 Mohr-Coulomb effective stress failure envelopes for

(a) kaolin clay; (b) bottom ash 137

4.9 a) Stress paths and CSL in q : p' space (b) CSL in e: p' space

for kaolin clay 139

4.10 Bottom ash particles at 10 µm magnification 141

4.11 Bottom ash particles at 100 µm magnification 141

5.1 Volume change against square-root time for consolidation

stage of controlled sample 145

5.2 Pore pressure dissipation against log time for consolidation

stage of controlled sample 146


stage of sample reinforced with single 10 mm diameter column

with 60 % height penetrating ratio 147







5.6 Pore pressure dissipation against log time for consolidation stage

of sample reinforced with single 16 mm diameter column with

60 % height penetrating ratio 150

5.7 Volume change against square-root time for consolidation stage

of sample reinforced with single 10 mm diameter column with

80 % height penetrating ratio 151

xix





stage of sample reinforced with single 16 mm diameter

column with 80 % height penetrating ratio 153

















stage of sample reinforced with group 10 mm diameter

columns with 60 % height penetrating ratio 158











xx









5.22 Pore pressure dissipation against log time for consol~dation















5.27 Time to reach full consolidation versus effective confining

pressure for (a) single and (b) group bottom ash columns 169

5.28 Schematic diagram on possible crushing and smearing effects of

different effective confining pressures on kaolin specimens

reinforced with bottom ash column 171

6.1 Shear strength versus area replacement ratio 178

6.2 Effect of ratio of column height to diameter on undrained shear

strength 181

6.3 The improvement of undrained shear strength by height

penetrating ratio for single and group bottom ash columns 182

6.4 Schematic diagrams of soft kaolin clay reinforced with

xxi

partially and fully penetrating granular columns,

confined by surrounding soil pressure 183

6.5 Improvement of undrained shear strength with volume

replacement ratio 184

6.6 Deviatoric stress and excess pore water pressure versus axial

strain for kaolin specimens reinforced with single bottom ash

columns at effective confining pressure of 100 kPa 188








strain for kaolin specimens reinforced with group bottom ash








6.12 Effective failure envelopes for kaolin specimens reinforced

with (a) single and (b) group columns 201

6.13 Effective friction angle versus height penetration ratio 202

6.14 Apparent cohesion versus height penetration ratio 203

6.15 Apparent cohesion versus area replacement ratio 206

6.16 Effective friction angle versus area replacement ratio 202

7.1 Effective stress paths for kaolin clay sample reinforced with

single and group bottom ash columns 210

7.2 (a) Stress paths and CSL in q: p' space and (b) CSL in

e: p' space for controlled sample 213

7.3 Critical state line in v : ln p' space for controlled sample 214

7.4 Effective stress paths for clay sample reinforced with single

xxi

partially and fully penetrating granular columns,

confined by surrounding soil pressure 183

6.5 Improvement of undrained shear strength with volume




















6.12 Effective failure envelopes for kaolin specimens reinforced

with (a) single and (b) group columns 201

6.13 Effective friction angle versus height penetration ratio 202

6.14 Apparent cohesion versus height penetration ratio 203

6.15 Apparent cohesion versus area replacement ratio 206

6.16 Effective friction angle versus area replacement ratio 202

7.1 Effective stress paths for kaolin clay sample reinforced with

single and group bottom ash columns 210

7.2 (a) Stress paths and CSL in q : p' space and (b) CSL in

e: p' space for controlled sample 213

7.3 Critical state line in v : ln p' space for controlled sample 214

7.4 Effective stress paths for clay sample reinforced with single

xx ii

bottom ash columns 215

7.5 (a) Stress paths and CSL in q : p' space (b) CSL in e: p'

space for clay sample reinforced with single 10 mm diameter

bottom ash column at 60 % penetration 217

7.6 CSL in v : In p' space for kaolin clay reinforced with single

10 mm diameter bottom ash columns with 60 % penetration 218

7.7 (a) Stress paths and CSL in q: p ' space (b) CSL in e: p '

space for clay sample reinforced with single 16 mm diameter

bottom ash column with 60 % penetration 219

7.8 CSL in v: ln p' space for kaolin clay reinforced with single


7.9 (a) Stress paths and CSL in q : p' space (b) CSL in e: p '

space for clay reinforced with single 10 mm diameter


7.10 CSL in v : In p' space for kaolin clay reinforced with single


7.11 (a) Stress paths and CSL in q: p' space (b) CSL in e : p'



7.12 CSL in v : ln p' space for kaolin clay reinforced with single


7.13 (a) Stress paths and CSL in q : p' space (b) CSL in e: p'



7.14 CSL in v: In p ' space for kaolin clay reinforced with single


7.15 (a) Stress paths and CSL in q: p' space (b) CSL in e: p '



7.16 CSL in v: ln p' space for kaolin clay reinforced with single


7.17 Effective stress paths for clay sample reinforced with group

bottom ash columns 229

7.18 (a) Stress paths and CSL in q: p ' space (b) CSL in e: p '

xxiii

space for clay reinforced with group 10 mm diameter

bottom ash columns with 60 % penetration 231

7.19 CSL in v: ln p' space for kaolin clay reinforced with

group 10 mm diameter bottom ash columns with 60 %

penetration 232

7.20 (a) Stress paths and CSL in q: p' space (b) CSL in e: p '



7.21 CSL in v: ln p' space for kaolin clay reinforced with group


7.22 (a) Stress paths and CSL in q: p' space (b) CSL in e: p'










7.26 (a) Stress paths and CSL in q : p' space (b) CSL in e : p'






space for clay reinforced with group of 16 mm diameter


7.29 CSL in v: ln p' space for kaolin clay reinforced with a group of

16 mm diameter bottom ash columns at 100 % penetration 242

7.30 Variation of (a) M, (b) r and ( c) A.; with volume replacement

ratio for kaolin clay reinforced with bottom ash columns 245

7.31 Variation of undrained shear strengths with volume

replacement ratio for all samples at p' 0 = 100 kPa 250

xx iv


replacement ratio for all samples at p' 0 = 200 kPa 251


replacement ratio for all samples at p ' 0 = 400 kPa 251

7.34 Variation of undrained shear strength with specific volume 254

7.35 Variation of volume replacement ratio with specific volume 256

7.36 Variation of undrained shear strength with volume replacement

ratio 258

7.37 Variation of the increased in undrained shear strength with

volume replacement ratio 259

7.38 Variation of undrained shear strength with volume


7.39 Correlation between a constant A and p' 0 262

7.40 Correlation between a constant Band p' 0 262

7.41 Design chart for undrained shear strength of kaolin clay

reinforced with bottom ash columns at various percentage of

volume replacement ratio 263

xxv

LIST OF APPENDICES

APPENDIX TITLE PAGE

A Calibration Certificate 285

B Hydrometer Test and Dry Sieving Test 294

c Atterberg Limit Test 296

D Relative Density Test 298

E Specific Gravity Test 299

F Standard 'Light' Compaction Test Data 300

G Permeability Test Data 301

H Direct Shear Test Data 303

I Unconfined Compression Test 307

J Consolidated Undrained Triaxial Test 320

AASHTO

ASTM

BA

BS

c CBR

CSL

CD

cu G

LL

NCL

PI

PL

SL

s SEM

UCT

us uses

LIST OF ABBREVIATIONS

American Association of State Highway and

Transportation Officials

American Society for Testing and Materials

Bottom Ash

British Standard

Controlled Sample

California Bearing Ratio

Critical State Line

Consolidated Drained

Consolidated Undrained

Group Columns

Liquid Limit

Normal Consolidation Line

Plasticity Index

Plastic Limit

Shrinkage Limit

Single Column

Scanning Electron Microscope

Unconfined Compression Test

United States

Unified Soil Classification System

XXVl

Documents

1 rnnnrn1 - Universiti Malaysia Pahang