Structural health monitoring of long-span suspension bridges

391 Pages·2011·5.623 MB·English

by  You-Lin Xu, Yong Xia

STRUCTURAL
HEALTH
MONITORING
OF LONG-SPAN
SUSPENSION
BRIDGES
YOU-LIN XU AND YONG XIA
Structural Health Monitoring of Long-Span
Suspension Bridges

Long-span suspension bridges cost billions. In recent decades, structural
health monitoring systems have been developed to measure the loading
environment and responses of these bridges in order to assess serviceability
and safety while tracking the symptoms of operational incidents and
potential damage. This helps ensure the bridge functions properly during a
long service life and guards against catastrophic failure under extreme
events.
Although these systems have achieved some success, this cutting edge
technology involves many complex topics which present challenges to
students, researchers, and engineers alike. Systematically introducing the
fundamentals and outlining the advanced technologies for achieving
effective long-term monitoring, this book covers

• the design of structural health monitoring systems
• finite element modelling and system identification
• highway loading monitoring and effects
• railway loading monitoring and effects
• temperature monitoring and thermal behaviour
• wind monitoring and effects
• seismic monitoring and effects
• SHMS-based rating method for long-span bridge inspection and
maintenance
• structural damage detection and test-bed establishment.

These are applied in a rigorous case study, using more than 10 year’s
worth of data, to the Tsing Ma suspension bridge in Hong Kong to examine
their effectiveness in the operational performance of a real bridge. The
Tsing Ma bridge is the world’s longest suspension bridge to carry both a
highway and railway, and is located in one of the world’s most active
typhoon regions. Bridging the gap between theory and practice, this is an
ideal reference book for students, researchers and engineering practitioners.
You-Lin Xu is Chair Professor, Head of the Department of Civil and
Structural Engineering, and founding Director of the Research Centre for
Urban Hazards Mitigation at the Hong Kong Polytechnic University.

Yong Xia is an Assistant Professor at the Hong Kong Polytechnic
University.
Structural Health Monitoring of Long-
Span Suspension Bridges

You-Lin Xu and Yong Xia
First published 2012
by Spon Press
2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN

Simultaneously published in the USA and Canada
by Spon Press
711 Third Avenue, New York, NY 10017

Spon Press is an imprint of the Taylor & Francis Group, an informa business

© 2012 You-Lin Xu and Yong Xia

The right of You-Lin Xu and Yong Xia to be identified as the authors of this work has been
asserted by them in accordance with sections 77 and 78 of the Copyright, Designs and
Patents Act 1988.

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.

This publication presents material of a broad scope and applicability. Despite stringent
efforts by all concerned in the publishing process, some typographical or editorial errors
may occur, and readers are encouraged to bring these to our attention where they represent
errors of substance. The publisher and author disclaim any liability, in whole or in part,
arising from information contained in this publication. The reader is urged to consult with
an appropriate licensed professional prior to taking any action or making any interpretation
that is within the realm of a licensed professional practice.

Trademark notice: Product or corporate names may be trademarks or registered trademarks,
and are used only for identification and explanation without intent to infringe.

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
Xu, You-Lin, 1952-
Structural health monitoring of long-span suspension bridges / You-Lin Xu and Yong Xia.
p. cm.
Includes bibliographical references and index.
1. Suspension bridges -- Testing. 2. Structural health monitoring. I. Xia, Yong, 1971- II.
Title.
TG400.X82 2012
624.2'30287 -- dc22

2011009700

ISBN: [978-0-415-59793-7] (hbk)
ISBN: [978-0-203-83966-9] (ebk)
This book has been prepared from camera-ready copy provided by the authors.
To Wei Jian, my wife

− Y.L. Xu

To Xiao Qing, my wife

− Y. Xia
Contents

Acknowledgements .............................................................................................. xiii 
Preface ................................................................................................................... xiv 
Foreword (1) .......................................................................................................... xvi 
Foreword (2) ....................................................................................................... xviii

CHAPTER 1 Introduction ........................................................................................ 1 
1.1 The Objective of Structural Health Monitoring ............................................. 1 
1.2 The History of Structural Health Monitoring of Bridges .............................. 3 
1.3 Recent Developments in Structural Health Monitoring................................. 8 
1.4 Organization of the Book .............................................................................. 8 
1.5 References ..................................................................................................... 9

CHAPTER 2 Long-span Suspension Bridges ........................................................ 12 
2.1 Preview ........................................................................................................ 12 
2.2 The History of Long-span Suspension Bridges ........................................... 12 
2.3 The Built Environment and Loading Conditions ......................................... 16 
2.3.1 Dead Load ............................................................................................ 16 
2.3.2 Railway Load ....................................................................................... 16 
2.3.3 Highway Load ..................................................................................... 16 
2.3.4 Temperature Effects ............................................................................. 17 
2.3.5 Wind Load ........................................................................................... 18 
2.3.6 Seismic Effects .................................................................................... 19 
2.3.7 Other Effects ........................................................................................ 19 
2.4 Structural Design, Construction and Maintenance ...................................... 20 
2.4.1 Structural System ................................................................................. 20 
2.4.2 Design Consideration and Criteria of Suspension Bridges .................. 21 
2.4.3 Construction of Suspension Bridges .................................................... 23 
2.4.4 Life-cycle Maintenance and Inspection of Suspension Bridges .......... 26 
2.5 The Tsing Ma Suspension Bridge in Hong Kong ........................................ 28 
2.5.1 Background .......................................................................................... 28 
2.5.2 Structural System ................................................................................. 28 
2.5.3 Design Considerations and Criteria ..................................................... 33 
2.6 References ................................................................................................... 36

CHAPTER 3 Structural Health Monitoring Systems ............................................. 39 
3.1 Preview ........................................................................................................ 39 
3.2 Design of Health Monitoring Systems ........................................................ 39 
3.3 Sensors and Sensing Technology ................................................................ 41 
3.3.1 Wind Measurement Sensors ................................................................ 41 
3.3.2 Seismic Sensors ................................................................................... 42
Contents vii
3.3.3 Weigh-in-motion Stations .................................................................... 43 
3.3.4 Thermometers ...................................................................................... 43 
3.3.5 Strain Gauges ....................................................................................... 44 
3.3.6 Displacement Measurement Sensors ................................................... 44 
3.3.7 Accelerometers .................................................................................... 46 
3.3.8 Weather Stations .................................................................................. 46 
3.3.9 Fibre Optic Sensors .............................................................................. 47 
3.3.10 Others ................................................................................................. 47 
3.4 Data Acquisition and Transmission System ................................................ 48 
3.4.1 Configuration of DATS ....................................................................... 48 
3.4.2 Hardware of DAUs .............................................................................. 49 
3.4.3 Network and Communication .............................................................. 50 
3.4.4 Operation of Data Acquisition and Transmission ................................ 51 
3.5 Data Processing and Control System ........................................................... 51 
3.5.1 Data Acquisition Control ..................................................................... 52 
3.5.2 Signal Pre-processing .......................................................................... 52 
3.5.3 Signal Post-processing and Analysis ................................................... 53 
3.6 Data Management System ........................................................................... 56 
3.6.1 Components and Functions of Data Management System .................. 57 
3.6.2 Maintenance of Data Management System .......................................... 58 
3.7 Wireless Sensor and Wireless Monitoring .................................................. 58 
3.7.1 Overview of Wireless Sensors ............................................................. 58 
3.7.2 Basic Architectures and Features of Wireless Sensors ........................ 59 
3.7.3 Challenges in Wireless Monitoring ..................................................... 61 
3.8 The Structural Health Monitoring System of the Tsing Ma Bridge ............ 61 
3.8.1 Overview of WASHMS ....................................................................... 61 
3.8.2 Anemometers in WASHMS ................................................................ 65 
3.8.3 Temperature Sensors in WASHMS ..................................................... 66 
3.8.4 Displacement Transducers in WASHMS ............................................ 66 
3.8.5 Level Sensing Stations in WASHMS .................................................. 67 
3.8.6 Global Positioning System in WASHMS ............................................ 68 
3.8.7 Strain Gauges in WASHMS ................................................................ 69 
3.8.8 Accelerometers in WASHMS .............................................................. 69 
3.8.9 Weigh-in-motion Stations in WASHMS ............................................. 70 
3.9 References ................................................................................................... 71 
3.10 Notations .................................................................................................... 74

CHAPTER 4 Structural Health Monitoring Oriented Modelling ........................... 76 
4.1 Preview ........................................................................................................ 76 
4.2 Modelling Technology ................................................................................ 76 
4.2.1 Theoretical Background ....................................................................... 76 
4.2.2 Spine Beam Model ............................................................................... 78 
4.2.3 Hybrid Model ....................................................................................... 80 
4.2.4 Modelling of Cables ............................................................................. 81 
4.3 System Identification ................................................................................... 82
viii Contents
4.3.1 Input-output Modal Identification Methods ......................................... 82 
4.3.2 Output-only Modal Identification Methods ......................................... 85 
4.4 Model Updating ........................................................................................... 86 
4.4.1 Overview .............................................................................................. 86 
4.4.2 Objective Functions and Constraints ................................................... 87 
4.4.3 Parameters for Updating ...................................................................... 89 
4.4.4 Optimization Algorithms ..................................................................... 90 
4.5 SHM-oriented Finite Element Model of the Tsing Ma Bridge .................... 92 
4.5.1 Modelling of the Bridge ....................................................................... 92 
4.5.2 Ambient Vibration Test of the Bridge ................................................. 98 
4.5.3 Sensitivity-based Model Updating of the Bridge ............................... 100 
4.6 References ................................................................................................. 103 
4.7 Notations .................................................................................................... 107

CHAPTER 5 Monitoring of Railway Loading Effects ........................................ 109 
5.1 Preview ...................................................................................................... 109 
5.2 Railway Monitoring System ...................................................................... 109 
5.3 Monitoring of Railway Traffic Condition and Load Distribution ............. 111 
5.4 Dynamic Interaction of Long-span Suspension Bridges with Trains ........ 112 
5.4.1 Vehicle Model.................................................................................... 112 
5.4.2 Bridge Model ..................................................................................... 114 
5.4.3 Wheel and Rail Interaction ................................................................ 115 
5.4.4 Numerical Solution ............................................................................ 118 
5.4.5 Stress Analysis ................................................................................... 118 
5.5 Monitoring of Railway Loading Effects on the Tsing Ma Bridge ............. 118 
5.5.1 Monitoring of Railway Traffic Condition .......................................... 120 
5.5.2 Monitoring of Railway Loading ........................................................ 121 
5.5.3 Monitoring of Railway Loading Effects on Bridge Displacements ... 123 
5.5.4 Monitoring of Railway Loading Effects on Bridge Accelerations .... 133 
5.6 Summary .................................................................................................... 138 
5.7 References ................................................................................................. 138 
5.8 Notations .................................................................................................... 139

CHAPTER 6 Monitoring of Highway Loading Effects ....................................... 141 
6.1 Preview ...................................................................................................... 141 
6.2 Highway Monitoring System ..................................................................... 142 
6.3 Monitoring of Highway Traffic Condition and Load Distribution ............ 143 
6.4 Dynamic Interaction of Long-span Suspension Bridges with Road Vehicles
......................................................................................................................... 143 
6.4.1 Modelling of Road Vehicles .............................................................. 144 
6.4.2 Modelling of Bridge........................................................................... 145 
6.4.3 Modelling of Road Surface Roughness ............................................. 146 
6.4.4 Principle of Computerized Approach ................................................ 147 
6.4.5 Equations of Motion of Coupled Vehicle-bridge System .................. 148 
6.4.6 An Example ....................................................................................... 148
Contents ix
6.5 Monitoring of Highway Loading Effects on the Tsing Ma Bridge ........... 152 
6.5.1 Data Processing ................................................................................. 152 
6.5.2 Monitoring of Highway Traffic Condition ........................................ 156 
6.5.3 Monitoring of Highway Loading Distribution ................................... 158 
6.5.4 Highway Loading Spectrum .............................................................. 161 
6.5.5 Strain Analysis and Fatigue Evaluation ............................................. 163 
6.6 Summary .................................................................................................... 172 
6.7 References ................................................................................................. 173 
6.8 Notations .................................................................................................... 174

CHAPTER 7 Monitoring of Temperature Effects ................................................ 177 
7.1 Preview ...................................................................................................... 177 
7.2 Temperature Monitoring ............................................................................ 178 
7.3 Heat-transfer Analysis ............................................................................... 180 
7.3.1 General Formulation .......................................................................... 180 
7.3.2 Thermal Boundary Conditions ........................................................... 180 
7.3.3 Solar Radiation .................................................................................. 181 
7.3.4 Equivalent Temperature ..................................................................... 184 
7.4 Temperature Effects on Long-span Suspension Bridges ........................... 184 
7.4.1 Temperature Effects on Static Behaviour of Bridges ........................ 184 
7.4.2 Temperature Effects on Dynamic Behaviour of Bridges ................... 185 
7.5 Monitoring of Temperature Effects on the Tsing Ma Bridge .................... 186 
7.5.1 Temperature Sensors in the Tsing Ma Bridge ................................... 186 
7.5.2 Heat-transfer Analysis of the Tsing Ma Bridge ................................. 189 
7.5.3 Temperature Distribution of the Tsing Ma Bridge ............................ 192 
7.5.4 Temperature-induced Displacement of the Tsing Ma Bridge ............ 199 
7.5.5 Temperature-induced Stress of the Tsing Ma Bridge ........................ 206 
7.5.6 Temperature Effect on Vibration Properties of the Tsing Ma Bridge 208 
7.6 Summary .................................................................................................... 211 
7.7 References ................................................................................................. 212 
7.8 Notations .................................................................................................... 214

CHAPTER 8 Monitoring of Wind Effects ........................................................... 216 
8.1 Preview ...................................................................................................... 216 
8.2 Wind Monitoring System .......................................................................... 216 
8.3 Monitoring of Boundary Layer Wind Environment .................................. 218 
8.3.1 Stationary Wind Model ...................................................................... 218 
8.3.2 Non-stationary Wind Model .............................................................. 220 
8.3.3 Time Varying Mean Wind Speed ...................................................... 220 
8.4 Wind Effects on Long-span Suspension Bridges ...................................... 221 
8.4.1 Buffeting Analysis of Long-span Suspension Bridges ...................... 221 
8.4.2 Flutter Analysis of Long-span Suspension Bridges ........................... 225 
8.4.3 Vortex Shedding Analysis of Long-span Suspension Bridges .......... 228 
8.5 Monitoring of Wind Effects on the Tsing Ma Bridge ............................... 229 
8.5.1 Monitoring of Wind Environment ..................................................... 230