Drilled Shafts in Rock Analysis and Design

Preface

1 Introduction

• 1.1 Definition of Drilled Shafts
• 1.2 Historical Development of Drilled Shafts
• 1.3 Use of Drilled Shafts
• 1.4 Characteristics of Drilled Shafts in Rock
• 1.4.1 Effect of discontinuities
• 1.4.2 Effect of groundwater
• 1.4.3 Effect of karstic formations
• 1.5 Considerations in the Design of Drilled Shafts

2 Intact rock and rock mass

• 2.1 Introduction
• 2.2 Intact Rock
• 2.2.1 Geological classification
• 2.2.2 Engineering classification
• 2.2.3 Typical values of intact rock properties
• 2.3 Rock Mass
• 2.3.1 Rock quality designation (RQD)
• 2.3.2 Rock mass rating (RMR)
• 2.3.3 Rock mass quality (Q)
• 2.3.4 Geological strength index (GSI)

3 Characterization of discontinuities in rock

• 3.1 Introduction
• 3.2 Types of Discontinuities
• 3.3 Important Properties of Discontinuities
• 3.4 Stereographic Projection
• 3.4.1 Hemispherical projection of a plane
• 3.4.2 Plotting and analysis of discontinuity orientation data
• 3.5 Statistical Analysis of Discontinuity Properties
• 3.5.1 Discontinuity orientation
• 3.5.2 Discontinuity spacing and frequency
• 3.5.3 Discontinuity trace length
• 3.5.4 Discontinuity size
• 3.6 Fracture Tensor for Describing Discontinuity Geometry

4 Deformability and strength of rock

• 4.1 Introduction
• 4.2 Deformability and Strength of Rock Discontinuities
• 4.2.1 Deformation behavior of rock discontinuities
• 4.2.2 Shear strength of rock discontinuities
• 4.3 Deformability of Rock Mass
• 4.3.1 Definition of modulus
• 4.3.2 Empirical methods for estimating rock mass deformation modulus
• 4.3.3 Equivalent continuum approach for estimating rock mass deformation modulus
• 4.3.4 Direct consideration of discontinuities in numerical analysis
• 4.4 Strength of Rock Mass
• 4.4.1 Empirical strength criteria for rock mass
• 4.4.2 Equivalent continuum approach for estimating rock mass strength
• 4.4.3 Direct consideration of discontinuities in numerical analysis
• 4.5 Scale Effect
• 4.5.1 Scale effect on strength of rock mass
• 4.5.2 Scale effect on deformability of rock mass
• 4.6 Discussion

5 Site investigation and rock testing

• 5.1 Introduction
• 5.1.1 Preliminary investigation
• 5.1.2 Detailed investigation
• 5.1.3 Review during construction and monitoring
• 5.2 Discontinuity Sampling on Exposed Rock Faces
• 5.2.1 Scanline sampling
• 5.2.2 Window sampling
• 5.2.3 Photographic mapping
• 5.3 Borings
• 5.3.1 Rock core boring
• 5.3.2 Inspecting borehole walls
• 5.3.3 Large-diameter borings
• 5.4 Exploratory Excavations
• 5.4.1 Test pits and trenches
• 5.4.2 Exploratory tunnels
• 5.5 Geophysical Explorations
• 5.5.1 General description
• 5.5.2 Seismic methods
• 5.5.3 Electrical resistivity method
• 5.5.4 Ground penetration radar
• 5.6 Laboratory Testing
• 5.7 In Situ Testing
• 5.7.1 General description
• 5.7.2 Strength tests
• 5.7.3 Deformability tests

6 Axial load capacity of drilled shafts in rock

• 6.1 Introduction
• 6.2 Capacity of Drilled Shafts Related to Reinforced Concrete
• 6.3 Capacity of Drilled Shafts Related to Rock
• 6.3.1 Side shear resistance
• 6.3.2 End bearing resistance
• 6.4 Capacity of Drilled Shaft Groups
• 6.5 Uplift Capacity

7 Axial deformation of drilled shafts in rock

• 7.1 Introduction
• 7.2 Load-transfer (t-z curve) Method
• 7.2.1 Linear analysis
• 7.2.2 Nonlinear analysis
• 7.3 Continuum Approach
• 7.3.1 Linear continuum approach
• 7.3.2 Nonlinear continuum approach
• 7.4 Finite Element Method (FEM)
• 7.5 Drilled Shaft Groups
• 7.5.1 Settlement ratio method
• 7.5.2 Equivalent pier method
• 7.5.3 Finite element method (FEM)

8 Lateral load capacity of drilled shafts in rock

• 8.1 Introduction
• 8.2 Capacity of Drilled Shafts Related to Reinforced Concrete
• 8.3 Capacity of Drilled Shafts Related to Rock
• 8.3.1 Method of Carter and Kulhawy (1992)
• 8.3.2 Method of Zhang et al. (2000)
• 8.4 Capacity of Drilled Shaft Groups
• 8.5 Discontinuum Method

9 Lateral deformation of drilled shafts in rock

• 9.1 Introduction
• 9.2 Subgrade-Reaction (p-y Curve) Approach
• 9.2.1 Linear analysis
• 9.2.2 Nonlinear analysis
• 9.2.3 p-y curves for rock
• 9.3 Continuum Approach
• 9.3.1 Linear continuum approach
• 9.3.2 Nonlinear continuum approach
• 9.4 Finite Element Method (FEM)
• 9.5 Discrete Element Method (DEM)
• 9.6 Drilled Shaft Groups
• 9.6.1 Deflection ratio approach
• 9.6.2 p-y curve approach
• 9.6.3 Finite element method (FEM)

10 Stability of drilled shaft foundations in rock

• 10.1 Introduction
• 10.2 Planar Sliding Failure
• 10.3 Wedge Sliding Failure
• 10.4 Toppling Failure
• 10.5 Circular Failure

11 Drilled shafts in karstic formations

• 11.1 Introduction
• 11.2 Characteristics of Karstic Formations
• 11.3 Investigation of Karstic Formations
• 11.4 Considerations in the Design and Construction of Drilled Shafts in Karstic Formations
• 11.5 An Example of Drilled Shaft Foundations in Karstic Formations

12 Loading test of drilled shafts in rock

• 12.1 Introduction
• 12.2 Axial Compressive Loading Test
• 12.2.1 General comments
• 12.2.2 Methods of applying loads
• 12.2.3 Instrumentation
• 12.2.4 Test procedures
• 12.2.5 Interpretation of test data
• 12.3 Axial Uplift Loading Test
• 12.4 Lateral Loading Test
• 12.4.1 General comments
• 12.4.2 Methods of applying loads
• 12.4.3 Instrumentation
• 12.4.4 Test procedures
• 12.4.5 Interpretation of test data
• 12.5 Integrity Test of Drilled Shafts

References

Index

Biography

Lianyang Zhang