An Introduction to Geotechnical Processes

342 Pages·2004·7.637 MB·\342

by  John Woodward (Author)

An Introduction to Geotechnical Processes

An Introduction to Geotechnical
Processes
JOHN WOODWARD

LONDON AND NEW YORK
First published 2005
by Spon Press
2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN
Simultaneously published in the USA and Canada
by Spon Press
270 Madison Ave, New York, NY 10016
Spon Press is an imprint of the Taylor & Francis Group
This edition published in the Taylor & Francis e-Library, 2005.

“To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of
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© 2005 John Woodward
All rights reserved. No part of this book may be reprinted or reproduced or
utilised in any form or by any electronic, mechanical, or other means, now
known or hereafter invented, including photocopying and recording, or in
any information storage or retrieval system, without permission in writing
from the publishers.
British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library
Library of Congress Cataloging in Publication Data
Woodward, John, 1936–
An introduction to geotechnical processes/John Woodward.—1st ed.
p. cm.
Includes bibliographical references and index.
1. Engineering geology. I. Title.
TA705. W66 2004
624.1′51–dc22 2004001287
ISBN 0-203-50488-7 Master e-book ISBN
ISBN 0-203-57136-3 (Adobe e-Reader Format)
ISBN 0-415-28645-X (hb: alk. paper)
ISBN 0-415-28646-8 (pb: alk. paper)
For Emily and George
PREFACE
Nowadays geotechnical processes are used in a range of civil engineering projects to
assist in construction by stabilising ground or to improve the load-carrying capacity of
foundations. Although numerous specialist publications and state-of-the-art dissertations
exist on the wide variety of topics involved, it is difficult to find one text dedicated solely
to bringing together for the non-specialist the most commonly used ground treatment
techniques. I have therefore endeavoured to address this gap and provide in this book a
concise and basic compendium of the essential practical information for as wide a
readership as possible at minimal cost. It is not a comprehensive design manual, but
rather a review of practical answers to questions raised by the non-specialist when faced
with making a decision on ground treatment—‘What bearing capacity can I expect
following treatment?’, ‘Can this soil be frozen and what about heave?’, ‘Will dynamic
compaction cause problems in the adjacent buildings?’, ‘Must I spend all this money on
ground investigation?’ and so on.
In offering guidance, as a practitioner rather than a theorist, on such diverse subjects, I
have had in mind the general civil and structural engineer who would like to be better
informed when turning to geotechnical specialists for assistance in dealing with difficult
ground conditions; also the developers, estimators and procurement personnel who need
to be familiar with the concepts when dealing with proposals from specialists and pricing
such works. In addition I hope this book will provide those civil engineering students and
engineering geologists who may be considering specialising in this interesting area of
construction with an introduction to practical foundation engineering.
‘Geotechnical processes’, for the purpose of this book, cover ground treatments and
improvements, generally undertaken by specialists, which use:
• extraction and exclusion of groundwater—typically by wells and cut-offs
• compaction techniques—by vibration and dynamic pounding and
• drilling and grouting techniques—by injecting self-setting fluids into ground
to stabilise ground, improve the support of structures and control settlement.
The complex subject of piling has not been considered as a geotechnical process for
this Introduction, except briefly where piles are used to form cut-off barriers. Reinforcing
of soils using geofabrics has not been included as this is usually undertaken directly by
the civil engineering contractor.
The text is based on the notes provided for a regular series of lectures given by the
author to post-graduate engineering geologists at Imperial College, London, and to
practising civil engineers over the past 10 years. These lectures were in turn based on
data collected, derived and researched from many sources during my career as a
geotechnical contractor and consultant, and these sources are acknowledged in the text
and fully referenced.
The format is a simple double-page layout (reduced or expanded to suit the scope
being considered), so that each of the processes considered will stand alone for reference.
This has inevitably led to retaining the lecture note style, rather than using a narrative
form, in order to give a broad and accessible view of what is currently available. Each
process is described and illustrated with cases and newly drawn diagrams, many based on
the author’s experience, under common headings ranging from the principle of the
process and its applications to construction methods, monitoring and plant capabilities.
There is some deliberate repetition of ground investigation requirements to remind
readers of the importance of accurate and appropriate data. Health and safety precautions
are also highlighted. Cross-references between sections are given in the form (4.1).
Although every effort has been made to use reliable sources and to verify the
information given, the ranges and limitations quoted for the various parameters,
conditions and improvements possible using the techniques discussed are unavoidably
fairly broad. Clearly no guarantees can be given here as so much depends on the specific
geology, context and application, and particularly on practical experience. Expert advice
should always be sought. The author is indebted to Dr Bryan Skipp for advice and
comments on the text, Dr Stephen Thomas of OGI (Oxford Geotechnica International)
for providing finite element analysis for solving fluid flow in soils, Mr lan Higginbottom
for reviewing the text and diagrams and providing geological notes, Mr Peter Constantine
for reviewing the soil mechanics and Mr Richard Miles of SeaMark Systems for an
update on offshore grouting.
Thanks are due to the following companies and individuals for granting permission to
use photographs and copyright material:
Bachy-Soletanche Ltd—photographs of reinforced earth in 9.4 and rotating cutters in
11.1.
Cementation Foundations Skanska Ltd—photographs of piled walls in 5.6and Vibwall
in 5.9.
Ischebeck-Titan—photographs of anchored sheet pile wall in 5.5 and abseiling in 9.3.
Dr D P McNicholl—diagram of slope drainage in 4.1.
© Pearson Education Limited 1983, 2000, reprinted by permission of Pearson
Education Limited. R Whitlow, Basic Soil Mechanics (1983, 2000)—diagrams of
shrinking/ swelling of clays in 1.6 and groundwater conditions in 3.1.
Dipl.-lng. H J Priebe—diagram of stone columns in 6.4.
SeaMark Systems Limited—photograph of the large jet mixer in 10.1 and diagram of
mixer in 11.2.
Sireg SpA—photograph of spiling in 9.5.
© Spon Press—stereogram in 1.4; depth of treatment by dynamic compaction in 6.5;
grout pressure diagram in 7.3; jet grout column diameter in 7.6; diagram of old mine
workings in 8.1; karst features in 8.3.
© Swets and Zeitlinger Publishers—groutability index in 7.1and arrangement of grout
circuits in 10.2.
Thomas Telford Limited—diagrams of Hong Kong diaphragm wall and cut-off at
Sizewell B in 5.4 and compensation grouting in 7.4.
© John Wiley & Sons, Inc., 1974. R B Peck, W E Hanson and T H Thornburn,
Foundation Engineering (1974)—extract from graph of SPT value versus relative density
in 1.2.
© John Wiley & Sons, Inc., 1992. J P Powers, Construction Dewatering—New
Methods and Applications (1992)—extract from eductor diagram in 4.5.
George Wimpey UK Limited—photographs in 1.7, 3.5, 4.1, 4.3, 4.5, 5.3, 6.3, 7.1, 8.3,
9.3 and 11.1.
Zschokle Services AG, Dietlikon—photographs of spraying shotcrete in 3.6, the
shotcrete wall in 5.6, the jet grouted support in 7.6, a jet grout monitor and grab in 11.1.
Extracts from BS 8081:1989 are reproduced with the permission of BSI under license
number 2003DH0301. British Standards can be obtained from BSI Customer Services,
389 Chiswick High Road, London, W4 4AL. Tel +44 (0)20 8996 9001. email:
[email protected].
J.C.W.
Princes Risborough 2004
SYMBOLS AND ABBREVIATIONS USED
The unit for stress and pressure used in this book is kN/m2 (kilonewtons per square
metre) or where appropriate (e.g. for unconfined compressive strength) N/mm2(newtons
per square millimetre) and MN/m2(meganewtons per square metre). Also used is the bar
unit of pressure when referring to injections and pump capabilities.

1 kN/m2=1 kPa (kilopascal in SI units)
1 N/mm2=1 MN/m2=1 MPa (megapascal)
1 bar=100 kN/m2
a width of a flow net square
A area
A area of stone column
c
A–D weathering grades for chalk
amp ampere
ASTM American Society for Testing and Materials
A drain cross-section area
w
b breadth of sliding black
B base area of temper
BH borehole
c, c u, c′ cohesion (shear strength), undrained shear strength,
drained shear strength
CCTV closed-circuit television
CDM Construction, Design and Management Regulations 1994
CE Civil Engineering grade of bentonite
CFA continuous flight auger
CFRP carbon fibre reinforced polymer
c coefficient of consolidation (horizontal)
h
COSSH Control of Substances Hazardous to Health (Regulations)
cp centipoise
CPT cone penetration test
c coefficient of consolidation
v
CWS continuous water-stop
c/c centre to centre
D diameter, or depth