liquefaction mitigation of silty soils using dynamic compaction

LIQUEFACTION MITIGATION OF SILTY SOILS USING DYNAMIC COMPACTION by RAFEEK NASHED December 19, 2005 A Dissertation submitted to the Faculty of the Graduate School of the State University of New York at Buffalo in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Civil, Structural & Environmental Engineering UMI Number: 3203924 3203924 2006 Copyright 2005 by Nashed, Rafeek UMI Microform Copyright All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, MI 48106-1346 All rights reserved. by ProQuest Information and Learning Company. Copyright by Rafeek G Nashed 2005 (ii) Dedication ________________________________________________________________________ iii DEDICATION To My Wife, My Children and My Mother Acknowledgements ________________________________________________________________________ iv ACKNOWLEDGEMENTS “Help me, O LORD my God And let them know that this is Your hand; You, LORD, have done it.” (Psalms 109:26, 27) First, I would like to forward my great thanks and praises to God. I offer my advisor Professor S. Thevanayagam, my most sincere gratitude for his continued support and advice throughout my studies and research efforts. His patience, encouragement and generosity are all greatly appreciated; working with him on this research has been an enlightening experience. I would like to thank my committee members, Professor P. K. Banerjee and Professor Shahid Ahmad for their patience, wisdom, and leadership. I also would like to express my deepest thanks and appreciation to Professor G. R. Martin for his contribution as my outside reviewer. I am especially thankful to my wife, who has been through it all with me. Thank you for all of your support, encouragement and love. Also thanks for my kids who have given my life a new purpose. Finally, financial support from my advisor through a grant from The Federal Highway Administration FHWA through The Multidisciplinary Center for Earthquake Engineering Research MCEER is gratefully acknowledged. iv Table of Contents ________________________________________________________________________ v TABLE OF CONTENTS Dedication………………………………………………………………………… iii Acknowledgements …………………………… ………………………………… iv Table of contents ………………………………………………………… …….… v List of Figures ………………………………………… …………… …… ……. xi List of Tables …………………………………………………… …….…… xxiv Notations …………………………………………….…………….……… …… xxvi Abstract ………………………………………………………………………… xxxvi 1. Introduction ……………… ……………………………………………….… … 1 1.1. Statement of the problem ………………………………………………… 5 1.2. Research scope and objectives…………………………………………… 9 1.3. Outline of dissertation ……………………………………………… … 10 2. Current Practice of Dynamic Compaction Technique …………………… … 12 2.1. Historical background………………………………………………….…. 12 2.2. Dynamic compaction applications ………… ……………………….… 13 Table of Contents ________________________________________________________________________ vi 2.2.1. Types of soil improved …………………………………….… 13 2.2.1.1. Granular and cohesive soils … ………………….…… 15 2.2.1.2. Collapsible soils ……………………………….…… 16 2.2.1.3. Other deposits ………………….….………….………. 17 2.2.2. Field observations ………………………………………… … 19 2.2.2.1. Depth of improvement ……………………….………. 19 2.2.2.2. Degree of improvement ………………………………. 20 2.2.2.3. Limits of improvement ……………………… ……… 23 2.2.3. Post-improvement assessment techniques ………………… …. 24 2.2.4. Induced Ground Subsidence ………………………….……… 28 2.2.5. Ground vibration ……… …………………………… ………. 30 2.3. Recent field advances …………… ……………………………………… 35 3. Current Practice Guidelines ……………………………………………………… 39 3.1. Introduction ………………………………………………………………. 39 3.2. Available design guidelines …………………… ………………………. 39 3.3. Summary and conclusion ………………………………………………… 46 4. Energy Dissipation mechanisms and Densification modeling …… ………… 48 4.1. Introduction ………………………………………………………………. 48 4.2. Energy dissipation mechanisms in granular media ……………….……… 48 4.2.1. Frictional dissipation mechanism ……………………………… 49 Table of Contents ________________________________________________________________________ vii 4.2.2. Viscous dissipation mechanism …………… …………………. 52 4.2.3. Particle breakage dissipation mechanism ……… ……………. 53 4.3. Densification due to DC ………………………… ……………………… 53 4.3.1. Densification modeling in dry deposits …………… ………… 53 4.3.2. Densification modeling in saturated deposits ……………… … 56 4.4. Past research on densification modeling due to DC …… ………… … 57 4.5. Summary ………………………………………………….……………… 63 5. Energy Attenuation Due to Surface Impact …………………………………… 65 5.1.Introduction ………………………………………………….………… … 65 5.2. Energy radiation due to surface impact……………………… ……… …. 66 5.2.1. Energy partitioning from surface impact in elastic half-space … 71 5.3. Attenuation relationships ………………… …………… ………………. 74 5.4. Energy dissipation due to DC processes …………… ……………………. 80 5.5. Summary and conclusions …………………………………….……………85 6. Proposed Densification Simulation Model ………………….……………… …. 87 6.1. Introduction ……………………… … ………………… …………… 87 6.2. Overview of the simulation model …………………… ……… ………. 87 6.3. Governing equations ………………………………………………… 92 6.4. Induced pore pressure due to energy dissipation …… …… …………… 93 6.5. Pore pressure dissipation ……………………… ……………………… 98 Table of Contents ________________________________________________________________________ viii 6.5.1. Boundary conditions ………………………….………………. 100 6.5.2. Convergence and stability ……………….……………………. 103 6.6. Soil Densification …………………………………….…… …………… 105 6.7. Modeling DC processes at a site …………………………….…………… 108 6.8. Summary ………………………… …………………………………… 112 7. Verification of the Proposed Model ……………………………….……………. 114 7.1. Introduction ………………………… ………………………………… 114 7.2. Kampung Paker site, Malaysia …………….…………………………… 115 7.3. Newport News, Virginia ………………… ……………… …………… 117 7.4. Steinaker dam modification project, Utah …………….….……………… 122 7.5. Conclusions ……………… …… ………………………… …………. 125 8. Effects of Site Conditions and Construction Procedure - Parametric study 127 8.1. Introduction ………………………… ………….……………………… 127 8.2. Effect of initial density of deposit (pre-(D r ) eq ) …………………….… … 132 8.3. Effect of deposit’s hydraulic conductivity (k) and fines content (FC) … 134 8.4. Effect of level of energy delivery WH ………… ………………… … 137 8.5. Effect of impact grid pattern …………………… ………………………. 139 8.6. Effect of impact print spacing S …………… …………………………… 143 8.7. Effect of number of impacts N I ………………………………… ……… 144 8.8. Effect of time cycle between impacts T ……………… ……………… 146 Table of Contents ________________________________________________________________________ ix 8.9. Effect of wick drains spacing S w …………… ………………… ……… 148 8.10. Summery and conclusions …………………………………… ………. 151 9. Design Guidelines for Dynamic Compaction of Silty Soils …………………… 153 9.1. Introduction …………………………………………………… … …… 153 9.2. Design procedure ……………………………… …… ……………… 154 9.3. Design charts ……………………………………………… ……………. 157 9.4. Regression analyses ………………………………… ………………… 168 9.4.1. Building and testing a model ……………………………… 169 9.4.2. Regression model …………………………… ………………. 171 9.5. Design examples …………………………………………………………. 173 9.5.1. Design example 1 ………………………………… ………… 174 9.5.2. Design example 2 ………………………………………… … 177 9.5.3. Design example 3 ………………………………………… … 180 9.5.4. Design example 4 ………………………………………… … 182 9.6. Summary and conclusions ……………………………………………… 184 10. Summary and Conclusions …………………………………………… ……… 186 10.1. Summary and major findings ……………… ………………… …… 186 10.2. Suggestions for future research …………………………………………. 190 [...]... …………………………………………………………………………… 263 List of Figures xi LIST OF FIGURES Figure 1-1 Examples of liquefaction damage ……………………………………… 3 Figure 1-2 Dynamic compaction process ………………………………………… 6 Figure 1-3 Dynamic compaction …………………………………… … …….… 8 Figure 2-1 Range of soil gradation of deposits suitable for DC ….… ………… 16 Figure 2-2 Maximum depth of influence versus drop energy...Table of Contents x Appendix A Penetration Resistance in Sands and Silty Sands ….…… …… … 192 Appendix B Energy Required to Cause Liquefaction … …………………… … 211 Appendix C Dynamic Compaction Simulation Software …….……………… … 220 Appendix D Software User Manual ………………………………………… … 227 Appendix E Simulation Results for A Dynamic Compaction Project ………... E-3 a) Pore pressure profile after impact No 8 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 234 Figure E-4 a) Pore pressure profile after impact No 4 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 235 Figure E-5 a) Pore pressure profile after impact No 8 b) Pore pressure profile List of Figures xxi ... profile after impact No 8 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 242 Figure E-12 a) Pore pressure profile after impact No 1 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 243 Figure E-13 a) Pore pressure profile after impact No 4 b) Pore pressure profile just before next impact c) Soil density profile... profile after impact No 8 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 250 Figure E-20 a) Pore pressure profile after impact No 4 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 251 Figure E-21 a) Pore pressure profile after impact No 8 b) Pore pressure profile just before next impact c) Soil density profile... profile after impact No 1 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 358 Figure E-28 a) Pore pressure profile after impact No 4 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 359 Figure E-29 a) Pore pressure profile after impact No 8 b) Pore pressure profile just before next impact c) Soil density profile... Pore pressure profile after impact No 4 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 361 Figure E-31 a) Pore pressure profile after impact No 8 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 362 List of Tables xxiv LIST OF TABLES Table 1-1 Recent major ground liquefaction. .. No 8 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 247 Figure E-17 a) Pore pressure profile after impact No 1 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 248 Figure E-18 a) Pore pressure profile after impact No 4 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location... No 8 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 239 Figure E-9 a) Pore pressure profile after impact No 1 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 240 Figure E-10 a) Pore pressure profile after impact No 4 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location... a) Pore pressure profile after impact No 1 b) Pore pressure profile just before next impact c) Soil density profile d) Impact location … 253 Figure E-23 a) Pore pressure profile after impact No 4 b) Pore pressure profile List of Figures xxiii just before next impact c) Soil density profile d) Impact location … 254 Figure E-24 a) Pore pressure profile after impact . LIQUEFACTION MITIGATION OF SILTY SOILS USING DYNAMIC COMPACTION by RAFEEK NASHED December 19, 2005 A Dissertation submitted to the Faculty of the Graduate School of the. ________________________________________________________________________ xi LIST OF FIGURES Figure 1-1 Examples of liquefaction damage ……………………………………… 3 Figure 1-2 Dynamic compaction process ………………………………………… 6 Figure 1-3 Dynamic compaction ……………………………………. ix 8.9. Effect of wick drains spacing S w …………… ………………… ……… 148 8.10. Summery and conclusions …………………………………… ………. 151 9. Design Guidelines for Dynamic Compaction of Silty Soils ……………………