U.S. Department of Transportation Federal Highway Administration

Publication No. FHWA-NHI-10-016 FHWA GEC 010 May 2010

NHI Course No. 132014

Drilled Shafts: Construction Procedures and LRFD Design MethodsDeveloped following:AASHTO LRFD Bridge Design Specifications, 4th Edition, 2007, with 2008 and 2009 Interims.

NOTICEThe contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect policy of the Department of Transportation. This report does not constitute a standard, specification, or regulation. The United States Government does not endorse products or manufacturers. Trade or manufacturer's names appear herein only because they are considered essential to the object of this document.

Technical Report Documentation Page1. Report No. 2. Government Accession No. 3. Recipients Catalog No.

FHWA NHI-10-0164. Title and Subtitle 5. Report Date

DRILLED SHAFTS: CONSTRUCTION PROCEDURES AND LRFD DESIGN METHODS NHI COURSE NO. 132014 GEOTECHNICAL ENGINEERING CIRCULAR NO. 107. Author(s)

May 20106. Performing Organization Code

8. Performing Organization Report No.

Dan A. Brown*, Ph.D, P.E., John P. Turner**, Ph.D, P.E., and Raymond J. Castelli, P.E.9. Performing Organization Name and Address 10. Work Unit No. (TRAIS)

PB Americas, Inc. One Penn Plaza, New York, NY 10119* **

11. Contract or Grant No.

Dan Brown and Associates, PLLC., Sequatchie, TN 37374 University of Wyoming, Laramie, WY 82071

DTFH-61-D-00011/T-07-00213. Type of Report and Period Covered

12. Sponsoring Agency Name and Address

National Highway Institute U.S. Department of Transportation Federal Highway Administration, Washington, D.C. 2059015. Supplementary Notes

14. Sponsoring Agency Code

FHWA COTR Louisa Ward/ Larry Jones FHWA Task Manager Silas Nichols, P.E. FHWA Technical Reviewers J. Maswoswe, Ph.D, P.E.; J. DiMaggio, P.E. and F. I. S. Ibrahim, Ph.D., P.E. See Acknowledgement for Additional Co-Authors, Contributors and Technical Reviewers This document is a major update and revision of the 1999 FHWA Drilled Shafts manual authored by Michael W. ONeill and Lymon C. Reese, Publication No. FHWA-IF-99-025.16. Abstract

This manual is intended to provide a technical resource for engineers responsible for the selection and design of drilled shaft foundations for transportation structures. It is used as the reference manual for use with the three-day National Highway Institute (NHI) training course No. 132014 on the subject, as well as the 10th in the series of FHWA Geotechnical Engineering Circulars (GEC). This manual also represents a major revision and update of the FHWA publication on drilled shaft foundations co-authored by the late Michael ONeal and late Lymon C. Reese, published in 1988 and revised in 1999. This manual embraces both construction and design of drilled shafts, and addresses the following topics: applications of drilled shafts for transportation structure foundations; general requirements for subsurface investigations; construction means and methods; LRFD principles and overall design process; geotechnical design of drilled shafts for axial and lateral loading; extreme events including scour and earthquake; LRFD structure design; field loading tests; construction specifications; inspection and records; non-destructive integrity tests; remediation of deficient shafts; and cost estimation. A comprehensive design example (Appendix A) is included to illustrate the step-by-step LRFD design process of drilled shafts as foundations for a highway bridge.17. Key Words 18. Distribution Statement

Drilled Shafts, LRFD, Foundations, Site Characterization, Geomaterial Properties, Axial Capacity, Lateral Capacity, Seismic, Scour, Structural Design, Construction, Soil, Rock, Specifications, Inspection, Integrity Testing, Field Loading Test, Remediation.19. Security Classif. (of this report) 20. Security Classif. (of this page)

No restrictions.

21. No. of Pages

22. Price

UNCLASSIFIEDForm DOT F 1700.7(8-72)

UNCLASSIFIEDReproduction of completed page authorized

970

CONVERSION FACTORSApproximate Conversions to SI Units When you know Multiply by To find (a) Length inch foot yard mile square inches square feet acres square miles fluid ounces gallons cubic feet cubic yards ounces pounds short tons (2000 lb) pound pounds per square foot pounds per square inch pounds per cubic foot Fahrenheit temperature(oF) 25.4 0.305 0.914 1.61 645.2 0.093 0.405 2.59 29.57 3.785 0.028 0.765 28.35 0.454 0.907 4.448 47.88 6.895 16.019 5/9(oF- 32) millimeter meter meter kilometer (b) Area square millimeters square millimeters square meters square meters hectares hectares square kilometers square kilometers (c) Volume milliliters milliliters liters liters cubic meters cubic meters cubic meters cubic meters (d) Mass grams grams kilograms kilograms megagrams (tonne) megagrams (tonne) (e) Force Newton Newton (f) Pressure, Stress, Modulus of Elasticity Pascals Pascals kiloPascals kiloPascals (g) Density kilograms per cubic meter kilograms per cubic meter (h) Temperature Celsius temperature(oC) Celsius temperature(oC) 0.0016 10.764 2.47 0.386 0.034 0.264 35.32 1.308 0.035 2.205 1.102 0.2248 0.021 0.145 0.0624 9/5(oC)+ 32 square inches square feet acres square miles fluid ounces gallons cubic feet cubic yards ounces pounds short tons (2000 lb) pound pounds per square foot pounds per square inch pounds per cubic feet Fahrenheit temperature(oF) millimeter meter meter kilometer 0.039 3.28 1.09 0.621 inch foot yard mile Approximate Conversions from SI Units When you know Multiply by To find

Notes: 1) The primary metric (SI) units used in civil engineering are meter (m), kilogram (kg), second(s), newton (N) and pascal (Pa=N/m2). 2) In a "soft" conversion, an English measurement is mathematically converted to its exact metric equivalent. 3) In a "hard" conversion, a new rounded metric number is created that is convenient to work with and remember.

ACKNOWLEDGMENTS This reference manual is a major update and revision of the very successful Federal Highway Administration (FHWA) publication on drilled shaft foundations co-authored by the late Michael W. ONeal and late Lymon C. Reese, published in 1988 and revised in 1999. Permission by the FHWA to include some original manuscripts and graphics from the previous versions is gratefully acknowledged. This reference manual provides the technical contents for the NHI 132014 Course Drilled Shafts developed by Parsons Brinckerhoff (PB) team including Dan Brown, John Turner, Ray Castelli. And C. Jeremy Hung. The Drilled Shafts course is also a major update and revision of the 2003 National Highway Institute (NHI) 132014 Course Drilled Shafts developed by PB and authored by late Michael W. ONeill, Dan Brown, & William Isenhower. The authors would like to acknowledge the overwhelming support of Louisa Ward, NHI Program Manager, and Silas Nichols, FHWA Task Manger, and the reviews and contributions from Jerry DiMaggio of the Strategic Highway Research Program (SHRP2) at the National Academies. Especially Mr. DiMaggios guidance and input prior to his retirement from FHWA in 2008, and his continuing support afterward have been invaluable. In addition, the authors thank the reviews and recommendations provided by the following individuals that served on the Technical Working Group for this project: Silas Nichols, P.E. Justice Maswoswe, Ph.D, P.E. Firas I. S. Ibrahim, Ph.D, P.E. Curtis Monk, P.E. Naser Abu-Hejleh, Ph.D, P.E. Peter Osborn, P.E. Naresh C. Samtani, Ph.D, P.E. FHWA FHWA FHWA FHWA FHWA FHWA NCS Consultants, Inc.

Furthermore, the authors thank the following organizations and their technical committees and representatives for providing valuable information and review of the manual: International Association of Foundation Drilling (ADSC-IAFD). Deep Foundation Institute (DFI) The Deep Foundations Committee of the Geo-Institute of ASCE Transportation Research Board

In addition, the authors are grateful for the generous contributions and reviews of John Bryson and Kwang Ro of PB, Anton Schindler of Auburn University, James Long of University of Illinois. Mr. K. Gifford Goodhue, Jr., of KB International, reviewed an early draft of Chapter 7 and offered many useful suggestions regarding the materials on use of drilling fluids in drilled shaft construction. Mr. Alan Macnab, Condon-Johnson & Associates, contributed the first draft of Section 22.5 on Contractor Cost Computations. Professor Fred H. Kulhawy, Cornell University, offered many useful suggestions and references on revisions to the beta-method for side resistance of drilled shafts in cohesionless soils presented in Chapter 13 and Appendix C. Lastly, the Authors would also like to extend our gratitude to the supports provided by a number of professionals from Parsons Brinckerhoff and Dan Brown and Associates, PLLC., including Lauren Chu Amy Pavlakovich, Matthew Smith, Alejandra Morales, and Maria Roberts of PB for their assistance and overall word processing and compiling.FHWA-NHI-10-016 Drilled Shafts Manual Acknowledgments May 2010

This page is intentional left blank.

TABLE OF CONTENTS

LIST OF FIGURES ...................................................................................................................................xiii LIST OF TABLES................................................................................................................................... xxiv CHAPTER 1 - OVERVIEW - SELECTION AND USE OF DRILLED SHAFT FOUNDATIONS FOR TRANSPORTATION STRUCTURES .....................................................................................1-1 1.1 1.2 1.3 1.4 INTRODUCTION - PURPOSE AND ORGANIZATION OF MANUAL ...............................1-1 TYPES OF DEEP FOUNDATIONS .........................................................................................1-3 DRILLED SHAFT FOUNDATIONS DESCRIPTION AND HISTORY..............................1-3 SELECTION OF DRILLED SHAFTS....................................................................................1-10 Applications .........................................................................................................................1-10 Advantages and Limitations.................................................................................................1-15

1.4.1 1.4.2 1.5 1.6

KEYS TO SUCCESSFUL USE OF DRILLED SHAFTS ......................................................1-15 SUMMARY .............................................................................................................................1-17

CHAPTER 2 - SITE CHARACTERIZATION .........................................................................................2-1 2.1 2.2 2.3 INTRODUCTION .....................................................................................................................2-1 ROLE OF THE GEOTECHNICAL ENGINEER......................................................................2-1 SITE CHARACTERIZATION PROGRAM .............................................................................2-3 Data Collection ......................................................................................................................2-3 Field Reconnaissance.............................................................................................................2-4 Detailed Field Investigations .................................................................................................2-5 Information Required for Construction................................................................................2-22 Geotechnical Investigation Report.......................................................................................2-24 Geotechnical Design Report ................................................................................................2-24 Data Presentation .................................................................................................................2-26 Differing Site Conditions .....................................................................................................2-27 Geotechnical Baseline Report..............................................................................................2-29 SUMMARY .........................................................................................................................2-29

2.3.1 2.3.2 2.3.3 2.3.4 2.4 2.4.1 2.4.2 2.4.3 2.4.4 2.4.5 2.4.6

GEOTECHNICAL REPORTS ................................................................................................2-24

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CHAPTER 3 - GEOMATERIAL PROPERTIES......................................................................................3-1 3.1 IN-SITU TESTING ...................................................................................................................3-1 Standard Penetration Test ......................................................................................................3-1 Cone Penetration Test ............................................................................................................3-5 Soil Index Properties and Classification ................................................................................3-8 Shear Strength Properties.......................................................................................................3-8 Deformation Properties ........................................................................................................3-14 Soil Erodibility.....................................................................................................................3-16 In-Situ State of Stress...........................................................................................................3-18 Unsaturated Soil Properties..................................................................................................3-19 Index Properties of Rock......................................................................................................3-21 Properties of Intact Rock......................................................................................................3-22 Strength of Rock Discontinuities .........................................................................................3-23 In-Situ Tests for Rock ..........................................................................................................3-23 Rock Mass Classification.....................................................................................................3-26 Engineering Properties of Rock Mass..................................................................................3-28 3.1.1 3.1.2 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.2.6 3.3 3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6 3.4 3.5

SOIL PROPERTIES ..................................................................................................................3-7

PROPERTIES OF ROCK........................................................................................................3-21

GEOMATERIALS REQUIRING SPECIAL CONSIDERATION .........................................3-30 GEOMATERAL PROPERTIES AND LRFD.........................................................................3-31

CHAPTER 4 - GENERAL CONSTRUCTION METHODS ....................................................................4-1 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 INTRODUCTION .......................................................................................................................4-1 DRY METHOD OF CONSTRUCTION .....................................................................................4-2 CASING METHOD OF CONSTRUCTION...............................................................................4-6 WET METHOD OF CONSTRUCTION ...................................................................................4-12 BASE GROUTING ...................................................................................................................4-17 UNDERREAMS (BELLS) ........................................................................................................4-20 BATTERED SHAFTS...............................................................................................................4-22 SUMMARY...............................................................................................................................4-23

CHAPTER 5 - TOOLS AND EQUIPMENT ............................................................................................5-1 5.1 5.2 5.2.1 INTRODUCTION ....................................................................................................................5-1 DRILLING MACHINES .........................................................................................................5-1 Overview of Rotary Systems................................................................................................5-2ii Table of Contents May 2010

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5.2.2 5.2.3 5.2.4 5.2.5 5.35.3.1

Mechanical vs Hydraulic Systems .......................................................................................5-3 Methods of Mounting Drilling Machine ..............................................................................5-3 Other Excavation Systems ...................................................................................................5-9 Summary ............................................................................................................................5-13 TOOLS FOR EXCAVATION ...............................................................................................5-13Rotary Tools .....................................................................................................................................5-13

5.3.2 5.4 5.4.1 5.4.2 5.4.3 5.4.4 5.5

Percussion and Other Tools................................................................................................5-25 OTHER TECHNIQUES .........................................................................................................5-29 Tools for Cleaning the Base of the Drilled Shaft Excavation ............................................5-29 Grouting .............................................................................................................................5-30 Soil Mixing.........................................................................................................................5-30 Concrete Liner....................................................................................................................5-31 SUMMARY ...........................................................................................................................5-32

CHAPTER 6 - CASING AND LINERS...................................................................................................6-1 6.1 6.1.1 6.1.2 6.1.3 6.1.4 6.2 6.2.1 6.2.2 6.2.3 6.2 TEMPORARY CASING..........................................................................................................6-1 Types and Dimensions .........................................................................................................6-1 Installation and Extraction of Temporary Casing ................................................................6-4 Possible Effects of Temporary Casing on Axial and Lateral Resistance ...........................6-10 Removing Casing after Concrete Sets................................................................................6-12 PERMANENT CASING........................................................................................................6-14 Types and Dimensions .......................................................................................................6-16 Installation of Permanent Casing .......................................................................................6-17 Effects of Permanent Casing on Axial and Lateral Resistance ..........................................6-17 SUMMARY ...........................................................................................................................6-18

CHAPTER 7 - DRILLING FLUIDS IN DRILLED SHAFT CONSTRUCTION.....................................7-1 7.1 7.2 7.2.1 7.2.2 7.2.3 7.2.4 7.3 INTRODUCTION AND BACKGROUND .............................................................................7-1 PRINCIPLES OF DRILLING FLUID PERFORMANCE FOR DRILLED SHAFTS ............7-2 Mineral Slurries....................................................................................................................7-2 Polymer Slurries...................................................................................................................7-5 Blended Slurries ...................................................................................................................7-8 Example Applications and Limitations of Drilling Fluids in Drilled Shaft Construction.........................................................................................................................7-9 MATERIAL CHARACTERISTICS AND SLURRY MIX DESIGN ...................................7-10iii Table of Contents May 2010

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7.3.1 7.3.1 7.4 7.4.1 7.4.2 7.4.3 7.4.4 7.5 7.5.1 7.5.2 7.5.3 7.5.4 7.6 7.7 7.6

Bentonite ..............................................................................................................................7-10 Polymers ..............................................................................................................................7-10 CONTROL OF DRILLING FLUID DURING CONSTRUCTION ......................................7-15 Mixing and Handling of Mineral Slurry ............................................................................7-15 Mixing and Handling of Polymer Slurry............................................................................7-17 Sampling and Testing.........................................................................................................7-19 Specifications for Drilling Slurry .......................................................................................7-27 ADDITIONAL DESIGN AND CONSTRUCTION CONSIDERATIONS...........................7-29 Borehole Inspection Under Drilling Fluids ........................................................................7-29 Influence of Slurry on Axial Resistance of Drilled Shafts .................................................7-29 Bond with Reinforcing Steel ..............................................................................................7-35 Summary of Major Handling Considerations ....................................................................7-36 SELECTION OF DRILLING FLUIDS .................................................................................7-38 EXAMPLES OF PROBLEMS AND SOLUTIONS WITH CONSTRUCTION UNDER DRILLING FLUIDS................................................................................................7-39 SUMMARY ...........................................................................................................................7-43

CHAPTER 8 - REBAR CAGES................................................................................................................8-1 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11 8.12 INTRODUCTION .....................................................................................................................8-1 PROPERTIES OF STEEL .........................................................................................................8-1 LONGITUDINAL REINFORCING..........................................................................................8-3 TRANSVERSE REINFORCING ..............................................................................................8-5 SPLICES ....................................................................................................................................8-8 CONNECTION BETWEEN DRILLED SHAFT AND COLUMN ........................................8-10 SIZING HOOPS ......................................................................................................................8-14 CENTERING DEVICES .........................................................................................................8-15 STRENGTHENING THE CAGE TO RESIST LIFTING FORCES.......................................8-16 ARRANGEMENTS FOR LIFTING CAGE............................................................................8-17 FABRICATION AND STORAGE..........................................................................................8-19 SUMMARY .............................................................................................................................8-21

CHAPTER 9 - PLACEMENT AND DESIGN OF CONCRETE FOR DRILLED SHAFTS ...................9-1 9.1 9.2 9.3 INTRODUCTION .....................................................................................................................9-1 BASIC CHARACTERISTICS OF DRILLED SHAFT CONCRETE.......................................9-1 PLACEMENT OF CONCRETE ...............................................................................................9-2iv Table of Contents May 2010

FHWA-NHI-10-016 Drilled Shafts Manual

9.3.1 9.3.2 9.3.3 9.3.4 9.3.5 9.4 9.5 9.6

Placement in a Dry Shaft Excavation...................................................................................9-3 Placement in a Dry Shaft Excavation within a Cased Hole .................................................9-6 Placement of Concrete in a Wet Excavation ........................................................................9-8 Records of Concrete Volume During Placement ...............................................................9-17 Completion of Concrete Placement at Shaft Head .............................................................9-18 DRILLING NEAR A RECENTLY CONCRETED SHAFT...................................................9-18 BASE GROUTING .................................................................................................................9-19 CONCRETE MIX DESIGN ....................................................................................................9-21 Cementitious Materials ........................................................................................................9-21 Chemical Admixtures ..........................................................................................................9-24 Aggregate and Water ...........................................................................................................9-26 Workability ..........................................................................................................................9-28 Control of Concrete Temperatures......................................................................................9-30 Mixture Proportions .............................................................................................................9-31 Communication of Project Specific Requirements for the Concrete ...................................9-38 Strength ................................................................................................................................9-39 Testing to Obtain Mixture Approval....................................................................................9-39 Tests at the Batch Plant........................................................................................................9-40 Addition of Water at Jobsite ................................................................................................9-42

9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.6.8 9.7 9.7.1 9.7.2 9.7.4 9.7

CONCRETE TESTS................................................................................................................9-39

9.7.3 Tests at the Jobsite ...............................................................................................................9-41 SUMMARY .............................................................................................................................9-39

CHAPTER 10 - LRFD FOR DRILLED SHAFT DESIGN.....................................................................10-1 10.1 10.2 10.3 10.4 INTRODUCTION TO LRFD ................................................................................................10-1 Development of Resistance Factors ................................................................................10-3 AASHTO LIMIT STATES AND LOAD COMBINATIONS ...............................................10-7 AASHTO LIMIT STATES AND DRILLED SHAFT RESISTANCES..............................10-10 RESISTANCE FACTORS FOR DRILLED SHAFTS ........................................................10-11 Summary of Resistance Factors...................................................................................10-11 Foundation Redundancy ..............................................................................................10-16 Comparison with Driven Piles .....................................................................................10-16 10.1.1

10.4.1 10.4.2 10.4.3 10.5 10.5

CALIBRATION TO REGIONAL CONDITIONS OR AGENCY PRACTICE..................10-16 SUMMARY .........................................................................................................................10-17

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CHAPTER 11 - DESIGN PROCESS ......................................................................................................11-1 11.1 11.2 OUTLINE OF THE OVERALL DESIGN AND CONSTRUCTION PROCESS .................11-1 SUMMARY .........................................................................................................................11-11

CHAPTER 12 - LATERAL LOADING..................................................................................................12-1 12.1 12.2 INTRODUCTION ...................................................................................................................12-1 EXAMPLES OF LATERAL LOADING ................................................................................12-1 Monoshaft Support for a Bridge Column.........................................................................12-1 Shaft Group Foundations for Bridge Structures...............................................................12-3 Drilled-Shaft-Supported Bridge Over Water ...................................................................12-4 Sound Walls, Sign Structures, High Mast Lighting .........................................................12-4 Foundation for a Bridge Abutment ..................................................................................12-5 Earth Retaining Structures ...............................................................................................12-7 Stabilization of a Moving Slope.......................................................................................12-8 Design Process .................................................................................................................12-9 Planning Stage Estimates ...............................................................................................12-12 Computational Procedures and Design Methodology....................................................12-15 Alternative Models for Computation of Shaft Response ...............................................12-42 Design of Drilled Shaft Walls ........................................................................................12-47 Design for Drilled Shaft Foundations with Lateral Movement of Soil Mass ................12-58

12.2.1 12.2.2 12.2.3 12.2.4 12.2.5 12.2.6 12.2.7 12.3 12.3.1 12.3.2 12.3.3 12.3.4 12.3.5 12.3.6 12.4

DESIGN FOR LATERAL LOADING....................................................................................12-9

SUMMARY ...........................................................................................................................12-62

CHAPTER 13 - AXIAL LOADING .......................................................................................................13-1 13.1 13.2 13.3 AXIAL LOAD TRANSFER BASIC CONCEPTS...............................................................13-1 RELATIONSHIP TO OVERALL DESIGN PROCESS .........................................................13-2 STEP-BY-STEP PROCEDURE: DESIGN FOR AXIAL LOAD ...........................................13-3 Idealized Geomaterial Layer Profiles...............................................................................13-5 Review Limit States and Factored Axial Loads...............................................................13-7 Geomaterial Properties and Loading Response Mode .....................................................13-7 Trial Designs ....................................................................................................................13-8 Calculate Nominal Side and Base Resistances ..............................................................13-10 Evaluate Trial Design for Strength Limit States ............................................................13-28 Evaluate Trial Design for Service Limit States..............................................................13-28 Final Trial Design for Axial Compression.....................................................................13-39vi Table of Contents May 2010

13.3.1 13.3.2 13.3.3 13.3.4 13.3.5 13.3.6 13.3.7 13.3.8

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13.4 13.5

DESIGN FOR UPLIFT...........................................................................................................13-39 DESIGN FOR SCOUR...........................................................................................................13-42 Background and Definitions ..........................................................................................13-42 Design Philosophy for Scour .........................................................................................13-43 Analysis and Prediction of Scour...................................................................................13-44 Application to Drilled Shaft Design...............................................................................13-46 Effects of Scour on Axial Resistance.............................................................................13-47 Occurrence .....................................................................................................................13-48 Downdrag Basic Concepts ..........................................................................................13-50 Analysis of Downdrag ...................................................................................................13-51 Downdrag Forces ...........................................................................................................13-54 Limit States Evaluation Under Downdrag .....................................................................13-55 Strategies to Address Downdrag....................................................................................13-57 Occurrence and Identification of Expansive Soils .........................................................13-58 Estimating the Zone of Seasonal Moisture Change .......................................................13-59 Design Solutions ............................................................................................................13-60

13.5.1 13.5.2 13.5.3 13.5.4 13.5.4 13.6 13.6.1 13.6.2 13.6.3 13.6.4 13.6.5 13.6.6 13.7 13.7.1 13.7.2 13.7.3 13.8

DOWNDRAG.........................................................................................................................13-48

DESIGN FOR EFFECTS OF EXPANSIVE SOIL ................................................................13-58

SUMMARY............................................................................................................................13-65

CHAPTER 14 - DESIGN OF GROUPS OF DRILLED SHAFTS..........................................................14-1 14.1 14.2 14.3 14.4 INTRODUCTION ....................................................................................................................14-1 GROUP VERSUS SINGLE SHAFT FOUNDATION.............................................................14-2 CONSIDERATIONS FOR SPACING .....................................................................................14-2 Group Effects on Axial Resistance ...........................................................................................14-3 Group Effects on Strength................................................................................................14-4 Settlement of Shaft Groups ..............................................................................................14-9 Group Effects in Rock and Cohesive IGM ....................................................................14-16 P-multiplier Concept ......................................................................................................14-16 Use of P-multiplier in Computer Codes..........................................................................14-18 Strain Wedge Approach .................................................................................................14-20

14.4.1 14.4.2 14.4.3 14.5 14.5.1 14.5.2 14.5.3

GROUP EFFECTS IN LATERAL LOADING......................................................................14-16

14.6 COMBINED LOADING AND COMPUTATION OF LOAD DISTRIBUTION TO GROUP ...................................................................................................................................14-20 14.6.1 Simple Static Equilibrium..............................................................................................14-21vii Table of Contents May 2010

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14.6.2 14.6.3 14.7

Simple Elastic Solution..................................................................................................14-23 Nonlinear Computer Solution ........................................................................................14-27

SUMMARY............................................................................................................................14-28

CHAPTER 15 - DESIGN FOR EXTREME EVENTS............................................................................15-1 15.1 15.2 DESIGN FOR EXTREME EVENT SCOUR ..........................................................................15-1 DESIGN FOR EARTHQUAKE ..............................................................................................15-2 Framework for Analysis of Earthquake Effects...............................................................15-2 Time-History Analysis.....................................................................................................15-8 Effects of Liquefaction.....................................................................................................15-9 Discussion of the AASHTO Guide Specifications for LRFD Seismic Bridge Design ............................................................................................................................15-12 15.3 DESIGN FOR EFFECTS OF ICE AND COLLISIONS .......................................................15-13 LRFD Framework for Extreme Event II........................................................................15-13 Determination of Force Effects on Drilled Shafts..........................................................15-14 15.3.1 15.3.2 15.4 15.5

15.2.1 15.2.2 15.2.3 15.2.4

DESIGN FOR COMBINED EXTREME EVENTS..............................................................15-17 SUMMARY ...........................................................................................................................15-18

CHAPTER 16 - STRUCTURAL DESIGN .............................................................................................16-1 16.1 12.2 INTRODUCTION ...................................................................................................................16-1 MATERIAL PROPERTIES ....................................................................................................16-3 Concrete ...........................................................................................................................16-3 Reinforcing Steel..............................................................................................................16-4 Casings.............................................................................................................................16-4

16.2.1 16.2.2 16.2.3 16.3 16.4 16.5 16.6

MINIMUM AND MAXIMUM AMOUNT OF LONGITUDINAL STEEL REINFORCEMENT ................................................................................................................16-4 MINIMUM AMOUNT OF TRANSVERSE STEEL REINFORMENT.................................16-5 CONCRETE COVER AND CAGE CENTERING DEVICES ...............................................16-7 CASES WITH AXIAL LOAD ONLY ....................................................................................16-7 Axial Compression...........................................................................................................16-7 Tension Members.............................................................................................................16-8 General Concepts .............................................................................................................16-9 Structural Design Procedure: Longitudinal and Transverse Reinforcement..................16-12 Depth of Transverse Reinforcement ..............................................................................16-17Table of Contents May 2010

16.6.1 16.6.2 16.6 16.7.1 16.7.2 16.7.3

CASES WITH AXIAL LOAD AND BENDING MOMENT .................................................16-9

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16.7.4 16.8 16.8.1 16.8.2 16.8.3

Splices, Connections, and Cutoffs .................................................................................16-18 Drilled Shafts with Rock Sockets ..................................................................................16-19 Drilled Shafts with Permanent Casing ...........................................................................16-21 Structural Analysis of Plain-Concrete Underreams .......................................................16-24

OTHER CONSIDERATIONS...............................................................................................16-19

CHAPTER 17 - FIELD LOADING TEST ..............................................................................................17-1 17.1 GENERAL .............................................................................................................................17-1 Benefits and Limitations of Field Load Testing ..............................................................17-2 Design-Phase Load Testing Program...............................................................................17-3 Field Load Testing Program at the Start of Construction ................................................17-4 Proof Tests on Production Shafts.....................................................................................17-4 Field Load Testing for Research ......................................................................................17-6 General Considerations in Planning Axial Load Tests ....................................................17-7 Test Methods..................................................................................................................17-16 Instrumentation ..............................................................................................................17-50 Interpretation of Axial Test Results for Design .............................................................17-61 General Considerations in Planning Lateral Load Tests................................................17-62 Test Methods and Procedures ........................................................................................17-64 Instrumentation ..............................................................................................................17-68 Interpretation of Lateral Test Data.................................................................................17-72 17.1.1 17.1.2 17.1.3 17.1.4 17.1.5 17.2 17.2.1 17.2.2 17.2.3 17.2.4 17.3 17.3.1 17.3.2 17.3.3 17.3.4 17.4

LOAD TESTS TO MEASURE AXIAL RESISTANCE .......................................................17-7

LOAD TESTS TO MEASURE LATERAL RESISTANCE................................................17-62

SUMMARY .........................................................................................................................17-73

CHAPTER 18 - GUIDE DRILLED SHAFT CONSTRUCTION SPECIFICATION.............................18-1 18.1 18.2 18.3 18.4 18.5 18.6 18.7 18.8 18.9 DESIGN CONSIDERATIONS..............................................................................................18-1 QUALIFICATIONS OF DRILLED SHAFT CONTRACTORS...........................................18-2 CONSTRUCTION METHOD ...............................................................................................18-2 DRILLING FLUID ................................................................................................................18-3 LOAD TESTING ...................................................................................................................18-3 INTEGRITY TESTING .........................................................................................................18-4 CONSTRUCTION PHASE SUBSURFACE INVESTIGATIONS .......................................18-5 DRILLED SHAFT INSTALLATION PLAN ........................................................................18-5 MEASUREMENT AND PAYMENT....................................................................................18-6Table of Contents May 2010

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18.10

SUMMARY ...........................................................................................................................18-7

CHAPTER 19 - INSPECTIONS AND RECORDS ................................................................................19-1 19.1 19.2 RESPONSIBILITIES .............................................................................................................19-1 INSPECTION ACTIVITIES..................................................................................................19-3 Set-Up ..............................................................................................................................19-6 Casing ..............................................................................................................................19-6 Drilling Fluid ...................................................................................................................19-7 Drilled Shaft Excavation..................................................................................................19-7 Placement of Reinforcement............................................................................................19-9 Concrete Placement........................................................................................................19-10 Completed Drilled Shaft ................................................................................................19-12

19.2.1 19.2.2 19.2.3 19.2.4 19.2.5 19.2.6 19.2.7 19.3 19.4 19.5 19.6

COMMON PROBLEMS......................................................................................................19-12 DIFFERING SITE CONDITION.........................................................................................19-14 RECORDS AND FORMS....................................................................................................19-14 SUMMARY .........................................................................................................................19-15

CHAPTER 20 - TESTS FOR COMPLETED DRILLED SHAFTS........................................................20-1 20.1 20.2 INTRODUCTION ..................................................................................................................20-1 NON-DESTRUCTIVE INTEGRITY TESTS........................................................................20-1 Sonic Methods .................................................................................................................20-2 Gamma-Gamma Method..................................................................................................20-9 Methods Based on Analysis of Stress Waves ................................................................20-13 Thermal Methods ...........................................................................................................20-19 Downhole Video Inspection...........................................................................................20-22

20.2.1 20.2.2 20.2.3 20.2.4 20.3 20.4 20.5 20.3.1

DRILLING AND CORING .................................................................................................20-20 LOAD TESTING FOR DRILLED SHAFT INTEGITY EVALUATION ..........................20-22 DESIGN OF AN INTEGRITY TESTING PROGRAM AND ACCEPTANCE CRITERIA............................................................................................................................20-23 When to Use NDT..........................................................................................................20-23 Evaluation of Defects and Acceptance Criteria .............................................................20-24

20.5.1 20.5.2 20.4 21.1 21.2

SUMMARY .........................................................................................................................20-22 INTRODUCTION ...............................................................................................................21-1 PROBLEMS PRIOR TO COMPLETION OF CONCRETE PLACEMENT......................21-4x Table of Contents May 2010

CHAPTER 21 - Remediation of Deficient Drilled Shafts .......................................................................21-1

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21.3 21.3.1 21.3.2 21.4 21.5 21.5.1 21.5.2 21.5.3 21.5.4 21.5.5 21.6

Types of Deficiencies in Completed Shafts .........................................................................21-4 Geotechnical Strength or Servicability ............................................................................21-5 Structural Strength ...........................................................................................................21-6 EVALUATION....................................................................................................................21-7 REMEDIATION METHODS..............................................................................................21-8 Ground Improvement.......................................................................................................21-9 Supplemental Foundations and/or Structural Bridging....................................................21-9 Excavation and Replacement .........................................................................................21-13 Structural Enhancement .................................................................................................21-13 Grouting .........................................................................................................................21-14 SUMMARY .......................................................................................................................21-18

CHAPTER 22 - COST ESTIMATION ...................................................................................................22-1 22.1 22.2 22.3 22.4 22.5 GENERAL .............................................................................................................................22-1 FACTORS INFLUENCING COST .......................................................................................22-1 COMMENTARY ...................................................................................................................22-4 HISTORICAL PRICE DATA AVAILABLE THROUGH THE INTERNET ......................22-4 CONTRACTORS' COST COMPUTATION .........................................................................22-7 Variable Costs................................................................................................................22-8 Jobsite Fixed Costs ........................................................................................................22-9 Overhead........................................................................................................................22-9 Contingencies.................................................................................................................22-9 Markup.........................................................................................................................22-10 Unit Prices....................................................................................................................22-10 Other Considerations ...................................................................................................22-10 Texas............................................................................................................................22-11 Washington ..................................................................................................................22-11

22.5.1 22.5.2 22.5.3 22.5.4 22.5.5 22.5.6 22.5.7 22.6 22.6.1 22.6.2

EXAMPLES .........................................................................................................................22-11

CHAPTER 23 - REFERENCES ..............................................................................................................23-1

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LIST OF APPENDICES APPENDIX A - DESIGN EXAMPLE FOR REPLACEMENT BRIDGE.............................................. A-1 APPENDIX B - GEOMATERIAL PROPERTIES FOR DRILLED SHAFTS IN SPECIFIC GEOLOGIC ENVIRONMENTS....................................................................................................... B-1 APPENDIX C - COMMENTARY ON METHODS FOR COMPUTING NOMINAL AXIAL RESISTANCE OF DRILLED SHAFTS ...................................................................... C-1 APPENDIX D - ANALYSIS OF AXIAL LOAD DEFORMATION RESPONSE ................................ D-1 APPENDIX E - DRILLED SHAFT LOAD TEST DATA...................................................................... E-1 APPENDIX F - SAMPLE DRILLED SHAFT INSPECTION FORMS, CHECKLISTS AND TABLES .........................................................................................................................F-1 APPENDIX G - STANDARD CIDH PILE ANOMALY MITIGATION PLAN .................................... G-1 APPENDIX H - ALTERNATIVE MODELS FOR ANALYSIS OF LATERAL LOADING................. H-1

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LIST OF FIGURES Figure 1-1 Figure 1-2 Figure 1-3 Figure 1-4 Figure 1-5 Figure 1-6 Figure 1-7 Figure 1-8 Figure 1-9 Figure 1-10 Figure 1-11 Figure 1-12 Figure 1-13 Figure 1-14 Figure 1-15 Figure 1-16 Figure 1-17 Figure 1-18 Figure 2-1 Figure 2-2 Figure 2-3 Figure 2-4 Figure 2-5 Figure 2-6 Figure 2-7 Figure 2-8 Figure 2-9 Figure 2-10 Figure 2-11 Figure 3-1 Figure 3-2 Figure 3-3 Figure 3-4 Figure 3-5 Figure 3-6 Figure 3-7 Figure 3-8 Figure 3-9 Figure 3-10 Figure 4-1 Figure 4-2 Figure 4-3 Figure 4-4 Figure 4-5 Figure 4-6 Figure 4-7 Figure 4-8 Holistic Design Example 1-2 Schematic of Axial and Lateral Resistance of a Drilled Shaft 1-4 Pneumatic Caisson for Firth of Forth Bridge 1-5 Caisson Construction for Greenville Bridge 1-6 Caisson Foundation Construction in Kansas City 1-6 Early Caisson Foundations 1-7 An Early Drilled Shaft Rig and Crew 1-8 Typical Modern Drilled Shaft Rigs 1-9 Construction of 12ft Dia. Drilled Shafts for the Main Pylon Foundation, Christopher S. Bond Bridge, Kansas City 1-9 Construction of Drilled Shaft in Dry, Cohesive Soils 1-11 Drilled Shafts for Bridge Foundations where Small Footprint is Desirable 1-11 Drilled Shafts for Individual Column Support over Water 1-12 Group of Drilled Shafts for Large Loads 1-12 Drilled Shafts Installed for Deep Scour Problem 1-13 Drilled Shafts with Low Headroom 1-13 Drilled Shafts for Soundwall and Sign 1-14 Drilled Shafts Used to Support Earth Retaining Structures 1-14 Drilled Shaft Secant Wall and Tangent Wall 1-15 Seismic Refraction Method 2-7 ReMi Seismic Velocity Profile 2-8 Field Configuration for Resistivity Test 2-8 Resistivity Tomogram, Pennsylvania Bridge Site in Karst 2-9 Common Sampling Devices for Soil 2-14 Field Photography of Rock Core 2-17 RQD Determination from Rock Core 2-17 Example of Key to Rock Core Log 2-20 Example of Key to Rock Core Log, continued from Figure 2-8 2-21 Example of Site Investigation Plan Location Map 2-27 Example Subsurface Profile for a Bridge Site 2-28 Schematic of Common In-Situ Tests 3-2 Split-Spoon Sampler for Determination of Soil Stratigraphy 3-4 Cone Penetration Test Equipment 3-6 Soil Behavior Type Classification Chart Based on Normalized CPT and CPTu Data 3-7 Typical Ranges of Friction Angle for Rockfills, Gravels, and Sands 3-11 Relationship Between ' and PI of Clay Soils 3-12 Example of Soil Stress-Strain Curve and 50% Secant Modulus 3-15 Erosion Function Apparatus and Measured Erosion Function 3-18 Typical Pressure-Dilation Graphs for a Pressuremeter Test in Rock 3-25 Chart for Determination of GSI for Jointed Rock Mass 3-27 Dry Hole in Stable Soil 4-3 Cuttings from a Dry Hole Spun off the Auger 4-4 Placement of Reinforcing Cage into the Excavation 4-5 Placement of Concrete into a Dry Excavation 4-5 Dry Method of Construction 4-6 Drilling into Rock through a Cased Hole 4-7 Construction Using Casing Through Slurry-Filled Starter Hole 4-8 Construction Using Casing Advanced Ahead of Excavation 4-8xiii Table of Contents May 2010

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Figure 4-9 Figure 4-10 Figure 4-11 Figure 4-12 Figure 4-13 Figure 4-14 Figure 4-15 Figure 4-16 Figure 4-17 Figure 4-18 Figure 4-19 Figure 4-20 Figure 4-21 Figure 4-22 Figure 4-23 Figure 4-24 Figure 5-1 Figure 5-2 Figure 5-3 Figure 5-4 Figure 5-5 Figure 5-6 Figure 5-7 Figure 5-8 Figure 5-9 Figure 5-10 Figure 5-11 Figure 5-12 Figure 5-13 Figure 5-14 Figure 5-15 Figure 5-16 Figure 5-17 Figure 5-18 Figure 5-19 Figure 5-20 Figure 5-21 Figure 5-22 Figure 5-23 Figure 5-24 Figure 5-25 Figure 5-26 Figure 5-27 Figure 5-28 Figure 5-29 Figure 5-30 Figure 5-31 Figure 5-32 Figure 5-33 Figure 5-34 Figure 5-35

Oscillator Rig Used to Advance Segmental Casing Ahead of the Excavation Use of a Vibro-Hammer and Twister Bar to Advance Casing Cutting Teeth on the Casing to Assist Penetration into the Bearing Stratum Breach of Casing/Concrete Seal During Casing Extraction Due to Cavity Telescoping Casing Slurry Provides Seepage Pressure Against Excavation Surface Slurry Drilling Process Use of Surface Casing to Overcome Artesian Groundwater Bottom Clean-out Bucket with Portal for Slurry Passage Wet Hole Construction Using Full Length Casing Reverse Circulation Drilling Schematic of Base Grout Process Base Grouting Systems Tied to Reinforcing Cage Pumping Grout to the Base of the Shaft Exhumed Shafts after Grouting Shapes of Typical Underreams An Early Drilled Shaft Machine and Crew Drill Rig Terminology Mechanical and Hydraulic Powered Drilling Machines Truck Mounted Drilling Rigs Crane Mounted Drilling Rig Crawler Mounted Drilling Rigs Excavator Mounted Drilling Machines for Restricted Overhead Conditions Oscillator Machine Rotator Machine Top-Drive Reverse Circulation Drill Reverse Circulation Cutting Heads for Top-Drive Drill Manual Excavation in Rock Excavation of a Diaphragm Wall or Barrette Using a Clam Excavation of a Diaphragm Wall or Barrette Using a Hydromill Single Flight Earth Augers Double Flight Earth Augers Large Diameter Auger with Double Cutting Edge Auger with Slurry Bypass Boulder Rooters Rock Augers Typical Drilling Buckets Clean-out Buckets Single Wall Core Barrels Double Wall Core Barrels Rock Cores Full-Faced Rotary Cutters Belling Buckets Special Rotary Tools: Grooving Tool and Backscratcher Boulder-Grabber Tool Clam-shell Buckets Hammergrabs Drop Chisels and Rock Breakers Downhole Impact Hammers Airlift and Hydraulic Pumps for Shaft Base Cleanout Use of Soil Mixed Columns in Conjunction with Drilled Shafts for a Wall

4-9 4-9 4-10 4-10 4-12 4-13 4-14 4-15 4-15 4-16 4-17 4-18 4-19 4-19 4-19 4-21 5-2 5-2 5-4 5-5 5-6 5-7 5-7 5-8 5-8 5-10 5-10 5-11 5-12 5-12 5-14 5-15 5-15 5-16 5-17 5-18 5-19 5-20 5-21 5-22 5-22 5-23 5-24 5-25 5-25 5-26 5-27 5-28 5-29 5-30 5-31

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Figure 5-36 Figure 6-1 Figure 6-2 Figure 6-3 Figure 6-4 Figure 6-5 Figure 6-6 Figure 6-7 Figure 6-8 Figure 6-9 Figure 6-10 Figure 6-11 Figure 6-12 Figure 6-13 Figure 6-14 Figure 6-15 Figure 6-16 Figure 7-1 Figure 7-2 Figure 7-3 Figure 7-4 Figure 7-5 Figure 7-6 Figure 7-7 Figure 7-8 Figure 7-9 Figure 7-10 Figure 7-11 Figure 7-12 Figure 7-13 Figure 7-14 Figure 7-15 Figure 7-16 Figure 7-17 Figure 7-18 Figure 7-19 Figure 8-1 Figure 8-2 Figure 8-3 Figure 8-4 Figure 8-5 Figure 8-6 Figure 8-7 Figure 8-8 Figure 8-9 Figure 8-10 Figure 8-11

Construction of Concrete-Lined Shaft 5-32 A Typical View of Stored Temporary Casing 6-2 Exceptionally Large Temporary Casings 6-3 Segmental Casing Installation with Oscillator System 6-4 Installation of Casing Joint on Standard Pipe 6-4 J Slots in Top of Casing for Use with Casing Twister 6-5 Teeth for Use in Sealing Casing into Rock 6-6 Use of Telescoping Casing 6-6 Extraction of Temporary Casing Using a Vibratory Hammer 6-8 Cutting Shoe for Segmental Casing 6-9 Adverse Effect of Casing Extended into Rock Socket 6-10 Exposed Surface of Drilled Shafts Constructed Using Oscillated and Rotated Casing 6-11 Locking Mechanism for a Removabnle Casing 6-13 Construction Joint Below the Water Surface 6-14 Example of Use of Permanent Casing 6-15 Permanent Casing Used for a Shaft Group Foundation in a River 6-16 Corrugated Metal Pipe (CMP) Used as Permanent Liner 6-17 Formation of Filter Cake and Positive Effective Pressure, Mineral Slurry in Sand Formation 7-3 Mineral Slurry Plates in Pores of Open-pored Formation 7-4 PAM Polymer Slurry 7-6 Stabilization of Borehole by the Use of Polymer Drilling Slurries 7-7 Schematic Diagram of Unit for Mixing and Treating Mineral Slurry 7-16 Field Mixing Polymer Slurry by Circulating Between Tanks 7-18 Techniques for Hanling Polymer Slurry 7-18 Device for Downhole Sampling of Slurry 7-20 Mud Density Balance for Field Measurement of Slurry Density 7-21 Marsh Funnel Test for Field Evaluation of Slurry Viscosity 7-22 Schematic of Slurry Viscometer 7-22 Interpretation of Data from a Viscometer Test 7-23 Photograph of Sand Content Test Apparatus 7-25 Average Load Transfer in Side Shear for Different Construction Methods 7-34 Mobilized Unit Side Resistance in Lower Fort Thompson Formation Rock Sockets 7-35 Placing Concrete through Heavily-Contaminated Slurry 7-40 Placing Casing into Mineral Slurry with Excessive Solids Content 7-40 Pulling Casing with Insufficient Head of Concrete 7-41 Placing Concrete where Casing was Improperly Sealed 7-42 GR75 Reinforcement Cage Being Assembled, Showing Threaded Couplers 8-3 View of a Rebar Cage Being Assembled, Showing Longitudinal Steel 8-4 View of Bundles of No.18 Rebar in a Drilled Shaft Cage 8-5 Transverse Ties and Spiral Steel, Showing Hook Anchors and Spiral Laps 8-6 Possible Distortion of Poorly Assembled Cage Due to Pickup Forces or Hydraulic Forces from Fresh Concrete 8-7 Examples of Inadequate Flow of Concrete Through Tightly Spaced Spiral Reinforcement 8-7 Bundled Hoops Used to Improve Flow of Concrete Through Transverse Reinforcement 8-8 Constructability Problem From Excessive Concentration of Lap Splices 8-9 Bar Couplers Used to Construct Splices 8-9 Adjustment to Drilled Shaft Reinforement for Alignment to Column Cage 8-10 Type I and II Connections 8-11Table of Contents May 2010

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Figure 8-12 Figure 8-13 Figure 8-14 Figure 8-15 Figure 8-16 Figure 8-17 Figure 8-18 Figure 8-19 Figure 8-20 Figure 8-21 Figure 8-22 Figure 8-23 Figure 8-24 Figure 9-1 Figure 9-2 Figure 9-3 Figure 9-4 Figure 9-5 Figure 9-6 Figure 9-7 Figure 9-8 Figure 9-9 Figure 9-10 Figure 9-11 Figure 9-12 Figure 9-13 Figure 9-14 Figure 9-15 Figure 9-16 Figure 9-17 Figure 9-18 Figure 9-19 Figure 9-20 Figure 9-21 Figure 9-22 Figure 9-23 Figure 9-24 Figure 9-25 Figure 9-26 Figure 9-27 Figure 9-28 Figure 9-29 Figure 10-1 Figure 10-2 Figure 11-1 Figure 12-1

Washington DOT Type II Connection Detail 8-12 Construction of a Type II Connection Detail over Water 8-13 Splice Cage Used to Fabricate Column to Shaft Connection 8-14 Sizing Hoop Assembly 8-14 Roller Centralizers on Reinforcing Cage 8-15 Chairs for Base of Reinforcing Cage 8-16 Transverse and Longitudinal Stiffeners for Temporary Strengthening of the Rebar Cage 8-17 Transverse Stiffeners Attached with Tack-Welds to Sizing Hoops 8-17 Photograph of Rebar Cage Being Lifted Improperly 8-18 Photograph of Rebar Cage Being Lifted Properly 8-18 Photograph of Rebar Cage Being Lifted with a Tipping Frame 8-19 Photograph of Rebar Cage Being Delivered to Site 8-20 Photograph of Rebar Cage Being Assembled Over the Shaft Excavation 8-20 Free Fall Concrete Placement in a Dry Excavation 9-3 Placement into a Dry Excavation Using a Drop Chute 9-4 Excessive Seepage Precludes Free Fall Placement of Concrete 9-5 Concrete Pressure Head Requirement During Casing Extraction 9-6 Slurry Displaced from Annular Space during Casing Extraction 9-7 Concrete Placement with Telescoping Casing 9-8 Tremie Must be Clean 9-9 Solid Tremie Pipes 9-10 Assembly of Segmental Tremie for Concrete Placement 9-10 Closure Plates for Closed Tremie 9-11 Control of Tremie to Establish Concrete Head 9-12 Breach of Tremie Due to Failure to Establish Concrete Head 9-12 Schematic of Concrete Vent Due to Loss in Concrete Mix Workability During Tremie Placement 9-13 Effects of Loss in Concrete Mix Workability During Tremie Placement 9-14 Pump Line Operations for Underwater Concrete Placement 9-15 Exposed Bottom Surface of an Exhumed Drilled Shaft 9-16 Example Concrete Volume Plots 9-17 Over-pour of the Shaft Top Until Clean Concrete is Revealed 9-18 Sleeve Port System for Distribution of Grout to the Base of the Shaft 9-20 Good Passing Ability is Required to Flow through Reinforcement 9-21 Simulated Effects of using SCMs on the Maximum Concrete Temperature Reached 9-23 The Effect of Different Initial Mixture Temperatures on the Temperature Development During Adiabatic Conditions 9-30 Slump Loss Relationship from a Trial Mixture Design 9-33 Concrete with Insufficient Workability for Use in Drilled Shafts 9-36 Concrete with High Workability but with Improper Mixture Design for Tremie Placement 9-37 Drilled Shaft Concrete with High Workability - 9.0 inch Slump 9-37 Drilled Shaft Concrete with Moderate Workability - 6.5 inch Slump 9-37 Self-consolidating Concrete with a 20 in. Slump Flow Used in Drilled Shaft Construction 9-38 3 9-40 Worksite Concrete Batch Plant Capable of Batching 130 yd /hr Reliability Concepts 10-5 Structural Analysis of Bridge Used to Establish Foundation Force Effects 10-9 Drilled Shaft Design and Construction Process 11-2 Single Column Piers with Monoshaft Foundations 12-2Table of Contents May 2010

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Figure 12-2 Figure 12-3 Figure 12-4 Figure 12-5 Figure 12-6 Figure 12-7 Figure 12-8 Figure 12-9 Figure 12-10 Figure 12-11 Figure 12-12 Figure 12-13 Figure 12-14 Figure 12-15 Figure 12-16 Figure 12-17 Figure 12-18 Figure 12-19 Figure 12-20 Figure 12-21 Figure 12-22 Figure 12-23 Figure 12-24 Figure 12-25 Figure 12-26 Figure 12-27 Figure 12-28 Figure 12-29 Figure 12-30 Figure 12-31 Figure 12-32 Figure 12-33 Figure 12-34 Figure 12-35 Figure 12-36 Figure 12-37 Figure 12-38 Figure 12-39 Figure 12-40 Figure 12-41 Figure 12-42 Figure 12-43 Figure 12-44 Figure 12-45 Figure 13-1 Figure 13-2 Figure 13-3 Figure 13-4 Figure 13-5

Monoshaft Foundations Used by Caltrans 12-2 Example of a Drilled Shaft Group Foundation for a Bridge 12-3 Drilled Shafts for Bridge Over Water, Somerset, KY 12-4 Elevation View of an Overhead Sign Structure 12-5 Sketch of Foundation for a Bridge Abutment 12-6 Drilled Shaft Abutment Foundations 12-6 Arch Bridge 12-7 Drilled Shaft Secant Wall and Tangent Wall 12-7 Drilled Shaft Foundation for Retaining Wall using Soldier Piles and Precase Panels 12-8 Drilled Shafts for Stabilizing a Slide 12-8 Analysis of Drilled Shafts in Moving Soil 12-9 Drilled Shaft Design Process for Lateral Loads 12-10 Equivalent Length Concept for Preliminary Design 12-13 Equivalent Length of Shaft for Preliminary Design of Single Shaft Foundation 12-13 Model of a Drilled Shaft Foundation Under Lateral Loading Showing Concept of Soil 12-17 Definition of Terms in Equations 12-6 and 12-7 12-21 Variation of EI of a Drilled Shaft Cross Section with Bending Moment and Axial 12-22 Stress-Strain Model for Concrete 12-23 Stress-Strain Model for Steel Reinforcement 12-23 Simple Lateral Load Example, Factored Loads Shown 12-27 Results of Analyses of Geotechnical Strength for Simple Example 12-28 Results of Analyses of Structural Strength and Serviceability for Simple Example 12-29 Bending Moment vs. Curvature for Simple Example 12-30 EI vs. Bending Moment for Simple Example 12-30 Conceptual p-y Curve for Cohesive Soil 12-31 Conceptual p-y Curve for Stiff Clay in the Presence of Free Water 12-32 Conceptual p-y Curve for Cohesionless Soil 12-33 Proposed p-y Criterion for Weak Rock 12-34 Proposed p-y Criterion for Strong Rock 12-35 Example for Sensitivity Analysis of Stratigraphy 12-36 Basic Strain Wedge in Uniform Soil 12-38 Deflection Pattern of Laterally Loaded Long Shaft and Associated Strain 12-38 Proposed Geometry of Compound Passive Wedge 12-39 Pushover Analysis of a Column Supported on a Drilled Shaft 12-41 Broms Earth Pressures for Cohesive Soils 12-43 Broms Pressure, Shear, Moment Diagrams for Cohesive Soils 12-43 Broms Pressure, Shear, Moment Diagrams for Cohesionless Soils 12-46 Secant, Tangent, and Soldier Pile Walls 12-47 Geometry for Drilled Shaft Wall 12-49 Simplified Earth Support Diagram for a Cantilever Wall using Effective Stress Strength 12-53 Example of Drilled Shaft Wall Problem 12-53 Earth Pressure Diagram for Drilled Shaft Wall Example Problem 12-55 Analysis of Drilled Shafts in Moving Soil 12-59 Spreading the Displaces Foundation with Soil 12-60 Generalized Load Transfer Behavior of Drilled Shaft in Compression 13-2 Flow Chart, Recommended Procedure for Axial Load Design 13-4 Idealized Geomaterial Layering for Computation of Compression Resistances 13-6 Frictional Model of Side Resistance, Drilled Shaft in Cohesionless Soil 13-11 Subsurface Profile and Drilled Shaft for Illustrative Example 13-1 13-14Table of Contents May 2010

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Figure 13-6 Figure 13-7 Figure 13-8 Figure 13-9 Figure 13-10 Figure 13-11 Figure 13-12 Figure 13-13 Figure 13-14 Figure 13-15 Figure 13-16 Figure 13-17 Figure 13-18 Figure 13-19 Figure 13-20 Figure 13-21 Figure 13-22 Figure 13-23 Figure 13-24 Figure 14-1 Figure 14-2 Figure 14-3 Figure 14-4 Figure 14-5 Figure 14-6 Figure 14-7 Figure 14-8 Figure 14-9 Figure 14-10 Figure 14-11 Figure 14-12 Figure 14-13 Figure 14-14 Figure 14-15 Figure 15-1 Figure 15-2 Figure 15-3 Figure 15-4 Figure 15-5 Figure 15-6 Figure 15-7 Figure 16-1 Figure 16-2 Figure 16-3 Figure 16-4 Figure 16-5

Soil Profile and Trial Shaft for Illustrative Example 13-2 13-18 Base Resistance Factor for Rock 13-22 Ground Profile and Trial Shaft for Illustrative Example 13-3 13-26 Factor for Cohesive IGM 13-27 Normalized Load-Displacement Curve, Drilled Shaft in Axial Compression 13-30 Idealized Subsurface Profile and Drilled Shaft Trial Dimensions 13-33 Mechanistic Model of Axially Loaded Drilled Shaft 13-38 Axially Loaded Shaft in Rock or Very Hard Geomaterial, Elastic Analysis 13-39 Typical Loading Combination Resulting in Uplift 13-41 Forces and Idealized Geomaterial Layering for Computation of Uplift Resistance 13-41 Components of Scour Affecting Bridge Supports on Deep Foundations 13-43 Flow Charts for Hydrology, Hydraulics, and Scour Analysis 13-45 Illustration of Scour Prism and Effects on Drilled Shaft 13-47 Downdrag on a Drilled Shaft Caused by Soil Settlement 13-50 Common Sources of Downdrag at Drilled Shaft Supported Bridge Abutments 13-50 Mechanics of Downdrag 13-51 Idealized Example of a Drilled Shaft in Expansive Ground 13-60 Use of embedded structural shape with weak concrete, Procedure B 13-62 Axial Force Effecrs and Resistances for Design of Drilled Shafts by Procedure C 13-63 Group of Drilled Shafts During Construction of the Benetia-Martinez Bridge near San Francisco 14-1 Group Versus Single Shaft 14-2 Overlapping Zones of Influence in a Frictional Pile Group 14-4 Block Type Failure Mode 14-6 Efficiency () vs. Center-to-Center Spacing (s), Normalized by Shaft Diameter (Bshaft), for Under Reamed Model Drilled Shafts in Compression in Moist, Silty Sand. 14-7 Relative Unit Side and Base Resistances for Model Single Shaft and Typical Shaft in a Nine-Shaft Group in Moist Alluvial Silty Sand 14-7 Axial Resistance from FE Model Results of Bored Pile Groups 14-8 Deeper Zone of Influence for End Bearing Shaft Group than for a Single Shaft 14-10 Equivalent Footing Concept for Pile Groups 14-13 Pressure Distribution Below Equivalent Footing for Pile Group 14-14 Typical e versus Log p Curve from Laboratory Consolidation Testing 14-15 The P-Multiplier Concept 14-17 Example Plots of Lateral Load Response by Row Position 14-19 Simple Static Analysis of a 2 x 2 Group 14-21 Simple Static Analysis of a 2 x 3 Group 14-23 Flowchart of Major Steps for Analysis of Drilled Shafts for Earthquake Effects 15-4 Response Spectrum for Determination of Seismic Response Coefficient 15-6 Relationship Between Connected Blow Count and Undrained Residual Strength (Sr) from Case Studies 15-11 Design Impact Force, Ship Colliding with Bridge Pier 15-16 Response Spectrum for Determination of Seismic Response Coefficient 15-12 Relationship Between Corrected Blow Count and Undrained Residual Strength (Sr) from Case Studies 15-17 Design Impact Force, Ship Colliding with Bridge Pier 15-21 Flow Chart for Structural Design 16-2 Transverse (Confinement) Reinforcement Details 16-7 Interaction Diagram for a Reinforced Concrete Column (a-h) 16-9 Nominal and Factored Interaction Diagrams 16-11 Variation of with Net Tensile Strain, t and dt/c for Grade 60 Reinforcement 16-12xviii Table of Contents May 2010

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Figure 16-6 Figure 16-7 Figure 16-8 Figure 16-9 Figure 16-10 Figure 16-11 Figure 16-12 Figure 16-13 Figure 17-1 Figure 17-2 Figure 17-3 Figure 17-4 Figure 17-5 Figure 17-6 Figure 17-7 Figure 17-8 Figure 17-9 Figure 17-10 Figure 17-11 Figure 17-12 Figure 17-13 Figure 17-14 Figure 17-15 Figure 17-16 Figure 17-17 Figure 17-18 Figure 17-19 Figure 17-20 Figure 17-21 Figure 17-22 Figure 17-23 Figure 17-24 Figure 17-25 Figure 17-26 Figure 17-27 Figure 17-28 Figure 17-29 Figure 17-30 Figure 17-31 Figure 17-32 Figure 17-33 Figure 17-34 Figure 17-35 Figure 17-36 Figure 17-37 Figure 17-38 Figure 17-39

Illustration of Terms bv, dv and dc for Circular Sections 16-14 SampleElevation of Drilled Shaft without Casing 16-16 Typical Sections without Casing 16-17 Comparison of Moment and Shear for a Cantilevered Column and a Socketed Drilled Shaft 16-20 Sample Elevation with Casing 16-22 Typical Section with Casing 16-23 Typical Underream 16-24 Tensile Stress Contours for Flat-bottom Bell 16-25 Kentledge Static Load Tests with Bi-directional Test and Rapid Load Test 17-1 Proof Test on Production Shafts can Verify Axial Resistance 17-5 Instrumental Research Load Tests 17-7 Observation of Test Shaft Excavation Helps Define Geologic Condition 17-10 Example Borehole Calipers & Logs; Mechanical and Sonic 17-12 Unit Side Shear vs Displacement for Drilled Shaft Sockets in Rock of Moderate Roughness with qu = 450 psi 17-14 Computed Relationship Between Shaft Diameter and Maximum Unit Side Shear Resistance for Rock Sockets 17-15 Chicago Method Load Test using Bi-directional Cell 17-15 Conventional Static Load Test on a Drilled Shaft 17-17 4,000 ton Capacity Reaction System 17-18 5,700 ton Capacity Load Test in Taiwan 17-18 Bi-DirectionalTesting Schematic 17-20 Example Test Result from Bi-Directional Test 17-21 O-Cell Test with Added Reaction System 17-21 Multiple-Level Arrangement for O-cells 17-22 Single O-Cell and Multiple O-Cell Assembly and Multi-Level O-Cell Assembly 17-23 Construction Of Equivalent Top-Loaded Settlement Curve 17-26 Top Down and O-Cell Load Test at a Soil Site 17-27 Effect of Shoulder at Top of Rock 17-27 Average Compressive Load in Shaft During Top Down and O-Cell Loading 17-28 17-28 Analytical Model Results for O-Cell Loading in a Rock Socket Analytical Model Results for O-Cell Loading in a Rock Socket 17-29 Comparison of Rapid Load and Hammer Blow 17-31 Conceptual Sketch of the Statnamic Rapid Load Test 17-32 Statnamic Loading Devices 17-32 Schematic Diagram of Statnamic Loading Apparatus 17-33 Statnamic Loading Apparatus 17-34 Measurements of Force and Displacement During Statnamic Loading 17-34 Force-Time Measurements for a Drilled Shaft 17-35 Single Degree of Freedom Model of a Statnamic Test 17-36 Statnamic Load versus Displacement 17-37 Computed Damping Coefficient, c 17-37 Segmental Unloading Point Method 17-38 Comparative Static and Statnamic Load Tests for Drilled Shafts 17-39 Dynamic Load Test of Drilled Shafts using Drop Weight and Pile Hammer 17-40 Transducers for Measurement of Force and Acceleration Photos courtesy of Pile Dynamics, Inc. 17-42 Signal Matching Concept 17-43 Computational Model of Shaft/Soil System 17-44 Factors Most Influencing CAPWAP Force Matching 17-45Table of Contents May 2010

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Figure 17-40 Figure 17-41 Figure 17-42 Figure 17-43 Figure 17-44 Figure 17-45 Figure 17-46 Figure 17-47 Figure 17-48 Figure 17-49 Figure 17-50 Figure 17-51 Figure 17-52 Figure 17-53 Figure 17-54 Figure 17-55 Figure 17-56 Figure 17-57 Figure 17-58 Figure 17-59 Figure 17-60 Figure 17-61 Figure 17-62 Figure 17-63 Figure 17-64 Figure 17-65 Figure 19-1 Figure 19-2 Figure 20-1 Figure 20-2 Figure 20-3 Figure 20-4 Figure 20-5 Figure 20-6 Figure 20-7 Figure 20-8 Figure 20-9 Figure 20-10 Figure 20-11 Figure 20-12 Figure 20-13 Figure 20-14 Figure 20-15 Figure 20-16 Figure 21-1 Figure 21-2

Impedance Profile of the Drilled Shaft is Required 17-45 CAPWAP Calculated Load Cycles for Four Blows on a 6ft Diameter Shaft 17-46 Arrangement for Testing a Drilled Shaft under Uplift Loading 17-48 Location of Reaction Mats Relative to Uplift Shaft in Rock 17-49 Uplift Shafts in Tension versuss Compression 17-50 Hydraulic Jacks for Static Load Tests 17-51 Dial Gauges 17-52 Telltales for Measurement of Displacement Below Shaft Top 17-54 Sister-bar Mounted Strain Gauges Placed in Drilled Shaft Reinforcement 17-55 Resistance Type Strain Gauge 17-56 Vibrating Wire Type Strain Gauge 17-57 Fiber Optic Strain Gauge with Bragg Grating 17-57 Example Plot of Force vs Elevation for a Top-Down Load Test 17-59 Example Plot of Unit Load Transfer Curves 17-60 Data from an Instrumented Field Load Test 17-60 Schematic Diagram of Lateral Test where Scourable Overburden is Present 17-63 Conventional Static Lateral Load Test Setup 17-65 Clevis Bracket and Load Cell Mount for Lateral Loading 17-66 Cyclic Lateral Load Test Setup 17-66 Bi-directional Lateral Testing Apparatus Using Embedded O-cells 17-67 Rapid Lateral Load Test 17-68 Long Travel Displacement Transducer 17-69 Measurements of Lateral Displacement in a Lateral Test Shaft below Grade Using an Inclinometer 17-70 In-Place Inclinometer Sensors 17-70 Down-hole Accelerometer for Displacement Measurement During Rapid Lateral Load Test 17-71 Strain Gauges to Measure Bending Moments 17-71 Setting Up a Sonic Caliper for Profiling a Drilled Shaft Shaft Inspection Device for Visual Inspection of the Shaft Bottom in a Wet Excavation Diagram of Crosshole Acoustic Logging System Crosshole Sonic Log for a Shaft with a Known Defect Reinforcing Cage with Steel Access Tubes for CSL Testing Crosshole Tomography Test 2-D Tomograms for a Shaft with Four Access Tubes Gamma-gamma Logging (GGL) in a Drilled Shaft Placement of PVC Access Tube Inside Reinforcing Cage Results from Gamma-gamma Logging of a Drilled Shaft with Four Access Tubes Defect similar to the defect that produced the logs in Figure 20-8 Sonic Echo Method A Severe Defect Likely to be Detected by Sonic Echo Testing Ideal Response Curve for the Impulse-response or Vibration Test Examples of Impedance Logs Concrete Cores Drilled Shafts Downhole Camera Used by Caltrans Drilled Shaft Acceptance Criteria Incorportating NDE Flow Chart of the Evaluation and Remediation Process Different Relative Stiffness of Different Deep Foundation Elements Affects Shear Forces in Cap 19-8 19-9 20-3 20-5 20-7 20-7 20-8 20-10 20-11 20-12 20-12 20-14 20-16 20-17 20-19 20-21 20-23 20-25 21-2 21-10

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Figure 21-3 Figure 21-4 Figure 21-5 Figure 21-6 Figure 21-7 Figure 21-8 Figure 21-9 Figure 21-10 Figure 21-11 Figure 21-12 Figure 21-13

Use of Straddle Shafts to Replace an Existing Foundation Use of Sister Shafts to Supplement an Existing Foundation Use of Micropiles Drilled Through Existing Drilled Shaft Use of Micropiles to Supplement an Existing Foundation Excavation and Replacement of Defective Concrete Using Drilling Tool within the Cage and Hand Methods Use of a Steel Section Cast into a Drilled Shaft to Form Structural Bridge Hydrodemolition Tools Downhole Camera View of Access Hole after Hydrodemolition Concrete Core Through Grouted Concrete Repair Jet Grouting and Illustration Jet Grouting Application for Drilled Shaft Repair

21-10 21-11 21-12 21-13 21-13 21-14 21-16 21-16 21-16 21-17 21-18

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LIST OF TABLES Table 1-1 Table 2-1 Table 2-2 Table 2-3 Table 2-4 Table 2-5 Table 2-6 Table 2-7 Table 2-8 Table 2-9 Table 3-1 Table 3-2 Table 3-3 Table 3-4 Table 3-5 Table 3-6 Table 3-7 Table 3-8 Table 3-9 Table 3-10 Table 7-1 Table 7-2 Table 8-1 Table 8-2 Table 9-1 Table 9-2 Table 9-3 Table 9-4 Table 10-1 Table 10-2 Table 10-3 Table 10-4 Table 10-5 Table 12-1 Table 12-2 Table 12-3 Table 13-1 Table 13-2 Table 13-3 Table 13-4 Table 14-1 Advantages and Limitations of Drilled Shafts 1-16 Summary of Field & Laboratory Methods for Geomaterial Characteristics 2-2 Sources and Use of Preliminary Project and Subsurface Information 2-4 Recommended Minimum Frequency of Borings, Drilled Shaft Foundations for Bridges 2-10 Methods of Boring and Sampling 2-13 Common Sampling Methods in Soil 2-14 Description of Rock Quality Based on RQD 2-18 Description of Rock Core for Engineering Characterization. 2-19 Information Used for Drilled Shaft Constructability 2-23 Information Included in Geotechnical Investigation Report 2-25 In-situ Tests in Soil with Application to Drilled Shaft Design 3-3 Soil Index Properties Used in Drilled Shaft Foundation Engineering 3-8 Relationship Between Relative Density, SPT N-Value, and Drained Friction Angle of Cohesionless Soils 3-10 Unconfined Compressive Strength of Particles for Rockfill Grades Shown in Figure 3-5 3-11 Common In-Situ Tests Used for Interpretation of su 3-13 Elastic Properties of Soils 3-17 In-Situ Tests Relevant to Shafts in Rock 3-24 Values of the Constant mi by Rock Group 3-29 Correlations Between GSI and Rock Mass Modulus 3-30 Values of Coefficient of Variation, V, for Geotechnical Properties and In-Situ Tests 3-32 Recommended Mineral Slurry Specifications for Drilled Shaft Construction 7-28 Recommended Polymer (PAM) Slurry Specifications for Drilled Shaft Construction 7-28 Properties of Reinforcing Steel for Concrete Reinforcement 8-2 Weights and Dimensions of Deformed Bars (Customary) 8-2 Example of Mixture Proportions for Workable Drilled Shaft Concrete 9-32 Examples of Mixture Proportiongs for "SCC" Type Drilled Shaft Concrete 9-32 Typical Proportions of Pozzolanic Additives 9-34 Typical Proportions of Some TxDOT Pre-approved Air Entraining Chemical Admixtures 9-35 Reliability Index in Terms of Probability of Failure 10-5 AASHTO (2007) Limit States for Bridge Design 10-7 Load Combinations and Load Factors 10-8 Load Factors and Permanent Loads 10-8 Summary of Resistance Factors for LRFD of Drilled Shaft Foundations 10-12 Recommended Resistance Factors for Geotechnical Strength Limit State for Lateral Loading of Drilled Shafts 12-25 Friction Angle for Mass Concrete Against Soil 12-50 Approximate Values of Relative Movements Required to Reach Active or Passive Earth Pressure Conditions 12-57 Geomaterial Properties Required for Drained and Undrained Axial Resistances 13-7 Bearing Capacity Factor N*c 13-19 Modulus Ratio from RQD 13-21 Method of Identifying Potentially Expansive Soils 13-59 Efficiency () for Model Drilled Shafts Spaced 3 Diameters Center-to-Center in Various Group Configurations in Clayey Sand (Senna et al, 1993) 14-8Table of Contents May 2010

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Table 14-2 Table 15-1 Table 15-2 Table 15-3 Table 15-4 Table 16-1 Table 16-2 Table 17-1 Table 17-2 Table 17-3 Table 17-4 Table 19-1 Table 19-2 Table 20-1 Table 20-2 Table 22-1 Table 22-2 Table 22-3 Table 22-4

Recommended P-Multiplier Pm Values for Design by Row Position Seismic Site Classification Based on Subsurface Profile Seismic Site Factors Seismic Risk Zones Load Combinations and Load Factors for Extreme Event Maximum Net Bearing Stresses for Unreinforced Concrete Underreams Minimum Yield Strengths for Permanent Steel Casing Summary of Benefits and Limitations of Design-Phase Field Load Tests Summary of Benefits and Limitations of Proof Tests on Production Shafts Summary of Benefits and Limitations of Proof Tests on Production Shafts Rate Factors for Different Soil Types Drilled Shaft Inspectors Checklist Common Problems Encountered During Drilled Shaft Construction Common NDT Methods for Drilled Shafts Concrete Condition Rating Criteria Low-Bid Table for Drilled Shafts, Texas DOT, Statewide Low-Bid Table for Drilled Shafts, Texas DOT; District 12 Only Average Low-Bid Prices for Drilled Shafts, 2007, Caltrans Summary Statistics on Drilled Shaft Contract, Ellis County, TX

14-18 15-5 15-5 15-7 15-17 16-4 16-25 17-3 17-4 17-6 17-38 19-4 19-13 20-2 20-5 22-5 22-6 22-7 22-11

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CHAPTER 1 OVERVIEW - SELECTION AND USE OF DRILLED SHAFT FOUNDATIONS FOR TRANSPORTATION STRUCTURES 1.1 INTRODUCTION - PURPOSE AND ORGANIZATION OF MANUAL

This publication is intended to provide a resource for engineers responsible for the selection and design of drilled shaft foundations for transportation structures and as a text for use with the three day short course on the subject presented by the National Highway Institute (Course No. 132014). This document represents an updated edition of the very successful Federal Highway Administration publication on drilled shaft foundations co-authored by the late Michael ONeal and late Lymon Reese, published in 1988 and revised and republished in 1999. The major changes to the manual include: The design approach follows the format of Load and Resistance Factor Design (LRFD) methods, consistent with the latest (2009) AASHTO standards. New information on site investigation and characterization for construction and design of drilled shafts, especially with respect to rock. New information on the evolution of construction techniques and materials, reflecting the increasing sizes and demands on drilled shaft foundations. Guidelines on the design and use of base grouting and new information on self consolidating concrete (SCC) materials in drilled shafts is included. Design for lateral and axial loading is expanded, and some design methods are