Centrifuge modelling for civil engineers

320 Pages·2014·5.758 MB·English

by  Madabhushi, Gopal

CIVIL ENGINEERING
“It is written in an engaging and accessible manner that will
be particularly useful in making non-specialists aware of the
benefits and applicability of centrifuge modelling to problems
of geotechnics and soil-structure interaction. In this way, I
believe it will play an important role in increasing the visibility
of the technique and its use by the civil engineering industry.”
—Jonathan Knappett, University of Dundee, UK
Centrifuge Modelling for Civil Engineers introduces centrifuge model-
ling to non-specialists and specialists. It begins with an introduction
to the design process in civil engineering and the role of structural
and geotechnical engineers. It draws on the complementarity of
numerical analyses and centrifuge testing. It presents the principles
of centrifuge modelling, starting with a brief introduction to the
mechanics of circular motion. It also explores scaling laws that relate
centrifuge model behaviour to field structures. The book describes
different types of geotechnical centrifuges and various systems of
model containers and actuators used. It provides a comprehensive
overview of the instrumentation used, data acquisition systems and
signal processing techniques employed to convert centrifuge test
data into physical observations in the model.
Centrifuge Modelling for Civil Engineers
The application chapters of the book describe centrifuge modelling
of shallow foundations, retaining walls, pile foundations and more
advanced centrifuge modelling used for construction processes. It
concludes by introducing the reader to the specialist aspects of
dynamic centrifuge modelling used to study dynamic problems such
as blast, wind or wave loading with an emphasis on earthquake
engineering, and including soil liquefaction problems.
Gopal Madabhushi is a professor of civil engineering and the
Director of the Schofield Centre at the University of Cambridge, UK.
Gopal Madabhushi
Building photo courtesy of jbor/Shutterstock.com
Centrifuge image courtesy of Jonathan Knappett
Y117656
ISBN-13: 978-0-415-66824-8
90000
9 780415 668248
Y117656_Cover.indd All Pages 7/3/14 12:11 PM

Centrifuge Modelling for Civil Engineers

Centrifuge Modelling for Civil Engineers
Gopal Madabhushi
A SPON BOOK
CRC Press
Taylor & Francis Group
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Version Date: 20140320
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To my parents for allowing me the freedom to pursue my dreams.
To my beloved Raji for supporting me every step of the way.
To Spandana for becoming an independent young doctor and for
not being too demanding on my time and Srikanth for coming
of age and discussing intelligently the contents of this book.

Contents
Foreword xiii
Preface xv
Acknowledgements xix
Author xxi
A historical perspective xxiii
1 Modern geotechnical engineering design in civil engineering 1
1.1 Introduction 1
1.2 Complex role of geotechnical engineers 3
1.2.1 Traditional safety factor–based design 4
1.2.2 Performance-based design 4
1.3 Role of centrifuge modelling 5
1.3.1 Use of centrifuge modelling in
safety factor–based designs 5
1.3.2 Use of centrifuge modelling in
performance-based designs 5
2 Need for numerical and physical modelling 7
2.1 Introduction 7
2.2 Use of numerical modelling in foundation design 8
2.3 Need for physical modelling 12
2.4 Benefits of centrifuge modelling 14
2.5 Benefits of numerical modelling 15
2.6 Complementarity of centrifuge modelling
and numerical modelling 16
2.6.1 Comparison of centrifuge data
with results from FE analysis 18
2.6.2 Deformed shape and horizontal stresses 19
2.7 Summary 21
vii
viii Contents
3 Uniform circular motion 23
3.1 Introduction 23
3.2 Uniform circular motion 24
3.3 Basic definitions: centripetal and centrifugal forces 26
3.4 Use of polar coordinates in uniform circular motion 27
3.5 Coriolis force and Euler force 30
3.6 Summary 31
4 Principles of centrifuge modelling 33
4.1 Introduction to centrifuge modelling 33
4.2 Principles of centrifuge modelling 34
4.3 Concepts of a field structure, prototype
and the centrifuge model 37
4.4 Scaling laws in centrifuge modelling 39
4.4.1 Derivation of simple scaling laws 39
4.4.2 Scaling law for time of consolidation 40
4.4.3 Scaling law for seepage velocity 43
4.4.4 Force, work and energy 44
4.5 Modelling of models 47
4.5.1 Centrifuge testing of shallow foundations 48
4.5.2 Bearing capacity 49
4.6 Summary 50
4.7 Examples 50
5 Geotechnical centrifuges: Some design considerations 53
5.1 Introduction to geotechnical centrifuges 53
5.2 Beam centrifuges 54
5.2.1 Examples of beam centrifuges 55
5.2.1.1 The Turner beam centrifuge
at Cambridge 55
5.2.1.2 The University of California,
Davis, centrifuge 56
5.2.1.3 U.S. Army Corps of Engineers centrifuge 58
5.2.1.4 National Geotechnical Centrifuge
Facility at Indian Institute
of Technology, Bombay 58
5.2.2 Size implications 59