1st Edition

Centrifuge Modelling for Civil Engineers

By Gopal Madabhushi Copyright 2015
    324 Pages 214 B/W Illustrations
    by CRC Press

    Solve Complex Ground and Foundation Problems

    Presenting more than 25 years of teaching and working experience in a wide variety of centrifuge testing, the author of Centrifuge Modelling for Civil Engineers fills a need for information about this field. This text covers all aspects of centrifuge modelling. Expertly explaining the basic principles, the book makes this technique accessible to practicing engineers and researchers.

    Appeals to Non-Specialists and Specialists Alike

    Civil engineers that are new to the industry can refer to this material to solve complex geotechnical problems. The book outlines a generalized design process employed for civil engineering projects. It begins with the basics, and then moves on to increasingly complex methods and applications including shallow foundations, retaining walls, pile foundations, tunnelling beneath existing pile foundations, and assessing the stability of buildings and their foundations following earthquake-induced soil liquefaction. It addresses the use of modern imaging technique, data acquisition, and modelling techniques. It explains the necessary signal processing tools that are used to decipher centrifuge test data, and introduces the reader to the specialist aspects of dynamic centrifuge modelling used to study dynamic problems such as blast, wind, or wave loading with emphasis on earthquake engineering including soil liquefaction problems.

    • Introduces the equipment and instrumentation used in centrifuge testing
    • Presents in detail signal processing techniques such as smoothing and filtering
    • Provides example centrifuge data that can be used for sample analysis and interpretation

    Centrifuge Modelling for Civil Engineers effectively describes the equipment, instrumentation, and signal processing techniques required to make the best use of the centrifuge modelling and test data. This text benefits graduate students, researchers, and practicing civil engineers involved with geotechnical issues.

    Modern geotechnical engineering design in civil engineering

    Introduction

    Complex role of geotechnical engineers

    Role of centrifuge modelling

    Need for numerical and physical modelling

    Introduction

    Use of numerical modelling in foundation design

    Need for physical modelling

    Benefits of centrifuge modelling

    Benefits of numerical modelling

    Complementarity of centrifuge modelling and numerical modelling

    Summary

    Uniform circular motion

    Introduction

    Uniform circular motion

    Basic definitions: centripetal and centrifugal forces

    Use of polar coordinates in uniform circular motion

    Coriolis force and Euler force

    Summary

    Principles of centrifuge modelling

    Introduction to centrifuge modelling

    Principles of centrifuge modelling

    Concepts of a field structure, prototype and the centrifuge model

    Scaling laws in centrifuge modelling

    Modelling of models

    Summary

    Examples

    Geotechnical centrifuges: Some design considerations

    Introduction to geotechnical centrifuges

    Beam centrifuges

    Drum centrifuges

    Summary

    Errors and limitations in centrifuge modelling

    Introduction

    Variation in gravity field

    Radial gravity field

    Particle size effects

    Strain rate effects

    Coriolis accelerations

    Summary

    Centrifuge equipment

    Model containers

    Model preparation techniques

    In-flight actuators

    In-flight soil characterization techniques

    Summary

    Centrifuge instrumentation

    Introduction

    Types of instruments

    Deformation measurement

    Summary

    Centrifuge data acquisition systems

    Introduction

    Analog to digital conversion

    Fundamentals of digital data logging

    Time and frequency domains

    Signal-to-noise ratio

    Aliasing and Nyquist frequency

    Filtering

    Summary

    Shallow foundations

    Introduction

    Bearing capacity of shallow foundations

    Modelling of a shallow foundation in a laboratory

    Centrifuge modelling of shallow foundations

    Modelling of models

    Summary

    Retaining walls

    Introduction

    Retaining wall models at laboratory scale

    Simulating retaining walls in a centrifuge

    Centrifuge testing of cantilever retaining walls

    Anchored retaining walls

    Centrifuge testing of L-shaped walls

    Centrifuge modelling of propped walls

    Summary

    Pile foundations

    Introduction

    Laboratory testing of pile foundations

    Centrifuge modelling of pile foundations

    Centrifuge modelling of pile installation

    Centrifuge modelling of laterally loaded piles

    Centrifuge modelling of tension piles

    Negative skin friction in piles

    Large-diameter monopiles

    Summary

    Modelling the construction sequences

    Advanced centrifuge modelling

    Construction sequence modelling

    Modelling of staged excavations in front of a retaining wall

    Modelling the interaction between a retaining wall and a building

    Influence of diaphragm walls on a pile foundation

    Modelling of propped retaining wall

    Tunneling below an existing pile foundation

    Tunneling below existing pipelines

    Tunneling below a masonry structure

    Summary

    Dynamic centrifuge modelling

    Modelling of dynamic events

    Dynamic scaling laws

    Discrepancies between general and dynamic scaling laws

    Earthquake simulation in centrifuges

    Saturation of centrifuge models

    Centrifuge modelling of the dynamic soil-structure interaction problems

    Centrifuge modelling of liquefaction problems

    Summary

    References

    Biography

    Dr Gopal Madabhushi is a professor of civil engineering at the University of Cambridge, UK and the director of the Schofield Centre. He has over 25 years of experience in the area of soil dynamics and earthquake engineering. His expertise extends from dynamic centrifuge modelling to the time domain finite element analyses of earthquake engineering problems, and has an active interest in the areas of soil liquefaction, soil-structure interaction, and liquefaction-resistant measures and their performances. Among other works he authored the geotechnical chapters in the book Seismic Design of buildings to Eurocode 8 (also published by Taylor & Francis).

    "The author, who is the current Director of the Schofield Centre, has summarised his experience of over 25 years and the wealth of knowledge in this specialist area accumulated at that institution into this book. Traditionally imparted exclusively for institutions with research centres of excellence in centrifuge modelling, this book makes this knowledge and know-how of modern geotechnical centrifuge modelling technology readily accessible to the wider civil engineering community… graduate students would find it an essential reference when embarking on their centrifuge modelling research. Practicing engineers who wish to learn about centrifuge modelling or who are about to launch into solving complex geotechnical problems would find this book readable and informative. Certainly, a worthwhile investment…"
    Proceedings of the Institution of Civil Engineers

    "This book will be very useful for research students. In most of the other books, very few topics are covered related to centrifuge modelling. However, in this book, a lot of important topics such as basic principles, limitation of centrifuge modelling, sample preparation, in-flight sample property determination, data acquisition, and applications in various areas are discussed. In this respect, the book is a complete package to researchers in this area as well as civil engineers who are keen to learn advanced physical modelling techniques."
    —Dr. Pradipta Chakrabortty, Indian Institute of Technology Patna

    "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