Contenido Single Piles and Pile Groups Under Lateral Loading

The complexities of designing piles for lateral loads are manifold as there are many forces that are critical to the design of big structures such as bridges, offshore and waterfront structures and retaining walls. The loads on structures should be supported either horizontally or laterally or in both directions and most structures have in common that they are founded on piles. To create solid foundations, the pile designer is driven towards finding the critical load on a certain structure, either by causing overload or by causing too much lateral deflection.

This second edition of Reese and Van Impe’s course book explores and explains lateral load design and procedures for designing piles and pile groups, accounting for the soil resistance, as related to the lateral deflection of the pile. It addresses the analysis of piles of varying stiffness installed into soils with a variety of characteristics, accounting for the axial load at the top of the pile and for the rotational restraint of the pile head. The presented method using load-transfer functions is currently applied in practice by thousands of engineering offices in the world. Moreover, various experimental case design examples, including the design of an offshore platform pile foundation are given to complement theory. The rich list of relevant publications will serve the user into further reading.

Designed as a textbook for senior undergraduate/graduate student courses in pile engineering, foundation engineering and related subjects, this set of book and CD-ROM will also benefit professionals in civil and mining engineering and in the applied earth sciences.

Contents

Techniques for design

Introduction

Occurrence of laterally loaded piles

Nature of the soil response

Response of a pile to kinds of loading

Models for use in analyses of a single pile

Models for groups of piles under lateral loading

Status of current state-of-the-art

Derivation of equations and methods of solution

Introduction

Derivation of the differential equation

Solution for Epy =kpyx

Validity of the mechanics

Models for response of soil and weak rock

Introduction

Mechanics concerning response of soil to lateral loading

Influence of diameter on p-y curves

Influence of cyclic loading

Experimental methods of obtaining p-y curves

Early recommendations for computing p-y curves

p-y curves for clays

p-y curves for sands above and below the water table

p-y curves for layered soils

p-y curves for soil with both cohesion and a friction angle

Other recommendations for computing p-y curves

Modifications to p-y curves for sloping ground

Effect of batter

Shearing force at bottom of pile

p-y curves for weak rock

Selection of p-y curves

Structural characteristics of piles

Introduction

Computation of an equivalent diameter of a pile with a noncircular cross section

Mechanics for computation of Mult and EpIp as a function of bending moment and axial load

Stress-strain curves for normal-weight concrete and structural steel

Implementation of the method for a steel h-section

Implementation of the method for a steel pipe

Implementation of the method for a reinforced-concrete section

Approximation of moment of inertia for a reinforced-concrete section

Analysis of groups of piles subjected to inclined and eccentric loading

Introduction

Approach to analysis of groups of piles

Review of theories for the response of groups of piles to inclined and eccentric loads

Rational equations for the response of a group of piles under generalized loading

Laterally loaded piles

Axially loaded piles

Closely-spaced piles under lateral loading

Proposals for solving for influence coefficients for closely-spaced piles under axial loading

Analysis of an experiment with batter piles

Analysis of single piles and groups of piles subjected to active and passive loading

Nature of lateral loading

Active loading

Single piles or groups of piles subjected to active loading

Passive loading

Single piles or groups of piles subjected to passive loading

Case studies

Introduction

Piles installed into cohesive soils with no free water

Piles installed into cohesive soils with free water above ground surface

Piles installed in cohesionless soils

Piles installed into layered soils

Piles installed in c-φ soil

Piles installed in weak rock

Analysis of results of case studies

Comments on case studies

Testing of full-sized piles

Introduction

Designing the test program

Subsurface investigation

Installation of test pile

Testing techniques

Loading arrangements and instrumentation at the pile head

Testing for design of production piles

Example of testing a research pile for p-y curves

Summary

Implementation of factors of safety

Introduction

Limit states

Consequences of a failure

Philosophy concerning safety coefficient

Influence of nature of structure

Special problems in characterizing soil

Level of quality control

Two general approaches to selection of factor of safety

Global approach to selection of a factor of safety

Method of partial factors (psf)

Method of load and resistance factors (LRFD)

Concluding comment

Suggestions for design

Introduction

Range of factors to be considered in design

Validation of results from computations for single pile

Validation of results from computations for pile group

Additional steps in design

APPENDICES

Broms method for analysis of single piles under lateral loading

Nondimensional coefficients for piles with finite length, no axial load, constant Ep/Ip, and constant Epy

Difference equations for step-tapered beams on foundations having variable stiffness

Computer Program COM622

Non-dimensional curves for piles under lateral loading for case where Epy =kpyx

Tables of values of efficiency measured in tests of groups of piles under lateral loading

Horizontal stresses in soil near shaft during installation of a pile

Use of data from testing uninstrumented piles under lateral loading to obtain soil response

Eurocode principles related to geotechnical design

Discussion of factor of safety related to piles under axial load