PREDICTION OF END BEARING FOR DRILLED SHAFTS AND SUGGESTION FOR DESIGN GUIDELINES OF END BEARING FOR DRILLED SHAFT IN FLORIDA LIMESTONE By SANG-HO KIM A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2003 Copyright 2003 by Sang-Ho Kim To My Mother and My Wife ACKNOWLEDGMENTS I thank God, at first, with all my heart. Without his leading, I would not be here right now. During my one year and eight months at the University of Florida, I have learned a lot of things and met many people. This period has been the most memorable and important time in my life. I would like to express my appreciation for all the professors (Dr. Michael C. McVay, Dr. Frank C. Townsend, Dr. David Bloomquist, Dr. Paul Bullock, Dr. John L. Davidson, and Dr. Bjorn Birgisson) in this department for giving me the opportunity to study here. In addition, I would like to extend a special thank to Professor Michael McVay for providing me the opportunity and for assisting me throughout the pursuit of my degree. He taught me many geotechnical concepts and how to think throughout our research when I was stuck. I would also like to thank all of my friends, Lila, Badri, Zhihong, Landy, Evelio, Minh, Erkan, Carlos, Thai, Scott, and Dinh, in our geotechnical field in civil engineering. It has been a pleasure studying with them and getting to know one another. In addition, I want to thank Sang-Min Lee, who helped me with the statistical aspects of this research, for being a good friend and colleague. Also, I would also like to thank Ben Watson of FDOT about lab testing for the data of our research. Finally, I would like to express the deepest thank to my family, my mother, my brothers, and my wife, who support me and pray for me every day. I especially appreciate iv my wife who has been a constant source of understanding and encouragement. We are expecting our first baby next January and can not wait to see her or him, as well. Since the beginning of my master’s course, many other people have helped me and encouraged me. Even though I could not list all their names here, their help and advice are not forgotten. I wish them all the best. v TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................................................................................. iv LIST OF TABLES............................................................................................................. ix LIST OF FIGURES ........................................................................................................... xi ABSTRACT..................................................................................................................... xiv CHAPTER 1 INTRODUCTION ........................................................................................................1 1.1 General....................................................................................................................1 1.2 Purpose and Scope..................................................................................................3 2 SITE DESCRIPTIONS.................................................................................................5 2.1 General....................................................................................................................5 2.2 17th Street Bridge...................................................................................................7 2.2.1 Site Description ............................................................................................7 2.2.2 General Soil Profile ......................................................................................7 2.3 Acosta Bridge .........................................................................................................8 2.3.1 Site Description ............................................................................................8 2.3.2 General Soil Profile ......................................................................................8 2.4 Apalachicola Bridge ...............................................................................................9 2.4.1 Site Description ............................................................................................9 2.4.2 General Soil Profile ......................................................................................9 2.5 Fuller Warren Bridge............................................................................................10 2.5.1 Site Description ..........................................................................................10 2.5.2 General Soil Profile ....................................................................................10 2.6 Gandy Bridge........................................................................................................11 2.6.1 Site Description ..........................................................................................11 2.6.2 General Soil Profile ....................................................................................11 2.7 Victory Bridge ......................................................................................................12 2.7.1 Site Description ..........................................................................................12 2.7.2 General Soil Profile ....................................................................................12 vi 3 LITERATURE REVIEW: OSTERBERG AND STATNAMIC TEST .....................13 3.1 General..................................................................................................................13 3.2 Osterberg Load Cell Test......................................................................................14 3.2.1 Summary of Osterberg Load Cell Test.......................................................14 3.2.1 Measurement of Osterberg Load Cell Test ................................................16 3.2.3 Advantage of the Osterberg Load Cell Test...............................................19 3.2.4 Limitations of the Osterberg Load Cell Test..............................................22 3.3 Statnamic Load Test .............................................................................................23 3.3.1 Summary of Statnamic Load Test ..............................................................23 3.3.2 Advantages and Disadvantages of the Statnamic Test ...............................24 4 LABORATORY TESTING .......................................................................................27 4.1 General..................................................................................................................27 4.2 Rock Cores Testing...............................................................................................27 4.2.1 Unconfined Compression Strength Test (qu) .............................................29 4.2.2 Tensile Strength Test (qt) ...........................................................................30 4.2.2.1 Brazilian test.....................................................................................30 4.2.2.2 Flexural test ......................................................................................33 4.2.2.3 Ring shear test ..................................................................................34 4.2.3 RQD (Rock Quality Designation) ..............................................................35 4.2.4 Percentage of Recovery (%).......................................................................36 4.2.5 Elastic Modulus Test (E)............................................................................37 5 ANALYSIS FOR LABORATORY DATA ...............................................................40 5.1 Sampling Size based on Rock Variability ............................................................40 5.2 Site Specific Laboratory Data...............................................................................43 5.2.1 17th Street Causeway ..................................................................................43 5.2.2 Acosta Bridge .............................................................................................47 5.2.3 Apalachicola River Sr 20............................................................................50 5.2.4 Fuller Warren Bridge..................................................................................53 5.2.5 Gandy Bridge..............................................................................................56 5.2.6 Victory Bridge............................................................................................59 5.3 Analysis of Relationship between coefficient of variation of qu and qt data.......62 5.4 Relationship between Recovery (%) and RQD (%) .............................................64 5.5 Correlation Between Rock Strength (qu & qt) with SPT N Values .....................65 6 PREDICTION OF UNIT END BEARING FOR DRILLED SHAFT .......................68 6.1 Prediction of End Bearing ....................................................................................68 6.2 Description of O’Neill(FB-Pier) Method .............................................................69 6.3 Prediction of the Unit End Bearing using the Nearest Boring..............................76 6.3.1 17th Street Causeway ..................................................................................76 6.3.2 Acosta Bridge .............................................................................................78