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Development of P-Y Criterion for Anisotropic Rock And DEVELOPMENT OF P-Y CRITERION FOR ANISOTROPIC ROCK AND COHESIVE INTERMEDIATE GEOMATERIALS A Dissertation Presented to The Graduate Faculty of the University of Akron In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Ehab Salem Shatnawi August, 2008 DEVELOPMENT OF P-Y CRITERION FOR ANISOTROPIC ROCK AND COHESIVE INTERMEDIATE GEOMATERIALS Ehab Salem Shatnawi Dissertation Approved: Accepted: ______________________________ ______________________________ Advisor Department Chair Dr. Robert Liang Dr. Wieslaw Binienda ______________________________ ______________________________ Committee Member Dean of the College Dr. Craig Menzemer Dr. George K. Haritos ______________________________ ______________________________ Committee Member Dean of the Graduate School Dr. Daren Zywicki Dr. George R. Newkome ______________________________ ______________________________ Committee Member Date Dr. Xiaosheng Gao ______________________________ Committee Member Dr. Kevin Kreider ii ABSTRACT Rock-socketed drilled shaft foundations are commonly used to resist large axial and lateral loads applied to structures or as a means to stabilize an unstable slope with either marginal factor of safety or experiencing continuing slope movements. One of the widely used approaches for analyzing the response of drilled shafts under lateral loads is the p-y approach. Although there are past and ongoing research efforts to develop pertinent p-y criterion for the laterally loaded rock-socketed drilled shafts, most of these p-y curves were derived from basic assumptions that the rock mass behaves as an isotropic continuum. The assumption of isotropy may not be applicable to the rock mass with intrinsic anisotropy or the rock formation with distinguishing joints and bedding planes. Therefore, there is a need to develop a p-y curve criterion that can take into account the effects of rock anisotropy on the p-y curve of laterally loaded drilled shafts. A hyperbolic non-linear p-y criterion for rock mass that exhibit distinguished transverse isotropy is developed in this study based on both theoretical derivations and numerical (finite element) parametric analysis results. Evaluations based on parametric study on full-scale lateral load test on fully instrumented drilled shaft have shown the insights on the influences of rock anisotropy on the predicted response of the rock socketed drilled shaft under the lateral load. Both, the orientation of the plane of transversely isotropy, and the degree of anisotropy (E/E’) has influences on the main two iii parameters required to characterize the p-y curve, the subgrade modulus (Ki) and the ultimate lateral resistance (pu). In addition to the development of a hyperbolic p-y criterion of transversely isotropic rock, another p-y criterion for cohesive intermediate geomaterials (IGM) using hyperbolic mathematical formulation is developed herein by employing the results of a series of finite element (FE) simulations and the results of two full scale lateral load test for drilled shaft socketed into IGM. iv DEDICATION To my mother, my father, my wife, my sisters and brothers, my friends, and to anyone who would read this dissertation. Also, I would like to dedicate this work to my expected baby. v ACKNOWLEDGEMENTS All praise is due to Allah (S.W.T) without whom nothing good of this work can be ever accomplished. Though only my name appears on the cover of this dissertation, a great many people have contributed to its production. I owe my gratitude to all those people who have made this dissertation possible and because of whom my graduate experience has been one that I will cherish forever. My deepest gratitude is to my advisor, Dr. Robert Liang. I have been amazingly fortunate to have an advisor who gave me the freedom to explore on my own and at the same time the guidance to recover when my steps faltered. I hope that one day I would become as good an advisor to my students as Prof. Robert Liang has been to me. Also of a great importance are the help and constructive comments and contributions I received from my committee members, Dr. Craig Menzemer, Dr. Daren Zywicki, Dr. Yueh- Jaw Lin, Dr. Xiaosheng Gao and Dr. Kevin Kreider. I would also like to acknowledge the support I received from personnel in our department, particularly Mrs. Kimberly Stone and Mrs. Christina. I must acknowledge as well the many friends, and colleagues, who assisted, advised, and supported me during these three and a vi half year. Especially, I need to express my gratitude and deep appreciation to my former roommate, Dr. Mohammad Yamin, whose friendship, knowledge, and wisdom have supported, enlightened, and entertained me over the ten years of our friendship. I must also acknowledge my former advisor, Dr. Abdulla Malkawi, I have learned so much from his keen insight, his research and problem solving abilities, and his amazing energy. Special thanks also to Dr. Jamal Nusairat, Dr. Diya Azzam, Dr. Inmar Badwan, Dr. Firas Hasan, Dr. Sami Khorbatli, Dr. Samer Rababa’a, Dr. Khalid Alakhras, Dr. Wael Khasawneh, Dr. Mohammad Khasawneh, Dr. Qais Khasawneh, Saleh Khasawneh, Abdallah Sharo, Wassel Bdour, Madhar Tamneh, Mohannad Aljarrah, Khalid Elhindi, Jamal Tahat, Khalid Mustafa, and my friends in Jordan, Eng. Kifah Ewisat, Eng. Mamoun Shatnawi, Eng. Mohammad Al-sakran, and Eng. Sameer Mousa. They have consistently helped me keep perspective on what is important in life and shown me how to deal with reality. Most importantly, none of this would have been possible without the love and patience of my family. My parents (Salem and Salmeh), my darling and lovely wife SAHAR, my sisters (Heba, Ruba, Waed, and the little and lovely one Lina) and brothers (Dr. Mohammad, Abdulla, Hussain, Dr. Murad, and Moad) to whom this dissertation is dedicated to, has been a constant source of love, concern, support and strength all these years. I would like to express my heart-felt gratitude to them. vii TABLE OF CONTENTS Page LIST OF TABLES.......................................................................................................... xiii LIST OF FIGURES .........................................................................................................xiv CHAPTER I. INTRODUCTION.........................................................................................................1 1.1 Statement of Problem ............................................................................................1 1.2 Objectives ..............................................................................................................8 1.3 Work Plan ..............................................................................................................9 1.4 Dissertation Outlines ...........................................................................................13 II. LITERATURE REVIEW...........................................................................................15 2.1 Analysis Methods of Laterally Loaded Rock-Socketed Drilled Shafts...............15 2.1.1 Elastic continuum methods........................................................................16 2.1.2 Winkler Method (Subgrade reaction approach) and P-Y method .............17 2.2 Analysis Methods for Estimating Ultimate Lateral Rock Reaction ....................22 2.2.1 Carter and Kulhawy (1992).......................................................................24 2.2.2 Zhang et al. (2000) ....................................................................................25 2.2.3 To, Ernst, and Einstein (2003)...................................................................26 2.2.4 Yang (2006)...............................................................................................27 2.3 Initial Modulus of Subgrade Reaction.................................................................30 2.4 Ultimate Side Shear Resistance...........................................................................32 viii 2.5 Discussion of Analytical Models for Laterally Loaded Sockets .........................35 2.6 Bedrocks ..............................................................................................................38 2.6.1 Rocks in Ohio............................................................................................38 2.6.2 Rock Characterization ...............................................................................39 2.6.3 Rock Categories.........................................................................................40 2.7 Laboratory and In-situ testing for Transversely Isotropic Rock..........................44 III. TRANSVERSE ISOTROPY EFFECTS ON THE INITIAL TANGENT TO P-Y CURVE.............................................................................................................................49 3.1 Abstract................................................................................................................49 3.2 Introduction..........................................................................................................50 3.3 Sensitivity Analysis .............................................................................................51 3.4 FE Analysis..........................................................................................................54 3.4.1 Description of FE Model...........................................................................54 3.4.2 Constitutive Models...................................................................................55 3.4.3 FE Analysis
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