Learning from Failure Long-term Behaviour of Heavy Masonry Structures WITPRESS WIT Press publishes leading books in Science and Technology. Visit our website for the current list of titles. www.witpress.com WITeLibrary Home of the Transactions of the Wessex Institute, the WIT electronic-library provides the international scientific community with immediate and permanent access to individual papers presented at WIT conferences. Visit the WIT eLibrary at http://library.witpress.com International Series on Advances in Architecture Objectives The field of architecture has experienced considerable advances in the last few years, many of them connected with new methods and processes, the development of faster and better computer systems and a new interest in our architectural heritage. It is to bring such advances to the attention of the international community that this book series has been established. The object of the series is to publish state-of-the- art information on architectural topics with particular reference to advances in new fields, such as virtual architecture, intelligent systems, novel structural forms, material technology and applications, restoration techniques, movable and lightweight structures, high rise buildings, architectural acoustics, leisure structures, intelligent buildings and other original developments. The Advances in Architecture series consists of a few volumes per year, each under the editorship - by invitation only - of an outstanding architect or researcher. This commitment is backed by an illustrious Editorial Board. Volumes in the Series cover areas of current interest or active research and include contributions by leaders in the field. Managing Editor F. Escrig Escuela de Arquitectura Universidad de Sevilla Spain Honorary Editors C. A. Brebbia P. R. Vazquez Wessex Institute of Technology Estudio de Arquitectura UK Mexico Associate Editors C. Alessandri K. Ishii University of Ferrara Yokohama National University Italy Japan F. Butera W. Jäger Politecnico di Milano Technical University of Dresden Italy Germany J. Chilton M. Majowiecki University of Lincoln University of Bologna UK Italy G. Croci S. Sánchez-Beitia University of Rome, La Sapienza University of the Basque Country Italy Spain A. de Naeyer J. J. Sendra University of Ghent Universidad de Sevilla Belgium Spain W. P. De Wilde M. Zador Free University of Brussel Technical University of Budapest Belgium Hungary C. Gantes R. Zarnic National Technical University of Athens University of Ljubljana Greece Slovenia K. Ghavami Pontificia Univ. Catolica, Rio de Janeiro Brazil Learning from Failure Long-term Behaviour of Heavy Masonry Structures Editor: L. Binda Politecnico di Milano, Italy Editor: L. Binda Politecnico di Milano, Italy Published by WIT Press Ashurst Lodge, Ashurst, Southampton, SO40 7AA, UK Tel: 44 (0) 238 029 3223; Fax: 44 (0) 238 029 2853 E-Mail: [email protected] http://www.witpress.com For USA, Canada and Mexico WIT Press 25 Bridge Street, Billerica, MA 01821, USA Tel: 978 667 5841; Fax: 978 667 7582 E-Mail: [email protected] http://www.witpress.com British Library Cataloguing-in-Publication Data A Catalogue record for this book is available from the British Library ISBN: 978-1-84564-057-6 ISSN: 1368-1435 Library of Congress Catalog Card Number: 2007922340 The texts of the papers in this volume were set individually by the authors or under their supervision. No responsibility is assumed by the Publisher, the Editors and Authors for any injury and/ or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. The Publisher does not necessarily endorse the ideas held, or views expressed by the Editors or Authors of the material contained in its publications. © WIT Press 2008 Printed in Great Britain by Athenaeum Press Ltd. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the Publisher. Contents Preface ............................................................................................................ xiii Chapter 1 Failures due to long-term behaviour of heavy structures........................... 1 L. Binda, A. Anzani & A. Saisi 1.1 Introduction ............................................................................................. 1 1.2 The collapse of the Civic Tower of Pavia: search for the cause .................................................................................................. 2 1.2.1 Description and historic evolution of the tower ......................... 3 1.2.2 First experimental results and interpretation of the failure causes .................................................................... 4 1.2.2.1 Structure and morphology of the walls....................... 4 1.2.2.2 Geotechnical investigation.......................................... 6 1.2.2.3 Physical, chemical and mechanical tests on the components ...................................................... 7 1.2.2.4 Compression tests on masonry prisms........................ 8 1.2.3 Long-term tests........................................................................... 9 1.2.3.1 Fatigue tests................................................................ 9 1.2.3.2 Constant load tests ...................................................... 11 1.3 Long-term behaviour of masonry structures........................................... 12 1.3.1 Deformation during mortar hardening........................................ 12 1.3.2 First, secondary and tertiary creep in rock and hardened masonry....................................................................... 15 1.4 Collapse and damage of towers due to long-term heavy loads............... 16 1.4.1 St. Marco bell-tower and St. Maria Magdalena tower in Goch ....................................................................................... 16 1.4.2 The bell-tower of Monza Cathedral and the Torrazzo of Cremona ................................................................................. 16 1.5 The role of investigation on the interpretation of the damage causes......................................................................................... 17 1.5.1 The bell-tower of the Cathedral of Monza ................................. 18 1.5.2 The ‘Torrazzo’ of Cremona........................................................ 21 1.6 Comparison between the two towers ...................................................... 25 1.7 Conclusions ............................................................................................. 26 Chapter 2 Experimental researches into long-term behaviour of historical masonry........................................................................................... 29 A. Anzani, L. Binda & G. Mirabella Roberti 2.1 Introduction ............................................................................................. 29 2.2 Tests on the masonry of the Civic Tower of Pavia ................................. 31 2.2.1 Characterization by sonic tests ................................................... 33 2.2.2 Monotonic tests on prisms of different dimensions ................... 33 2.2.3 Fatigue tests................................................................................ 35 2.2.4 Creep tests on prisms of 300 × 300 × 510 mm........................... 36 2.2.5 Pseudo-creep tests on prisms of 100 × 100 × 180 mm............... 39 2.2.6 Pseudo-creep tests on prisms of 200 × 200 × 350 mm............... 39 2.3 Tests on the masonry of the crypt of the Cathedral of Monza................ 42 2.3.1 Preparation of prisms of 200 × 200 × 350 mm........................... 42 2.3.2 Characterization by sonic tests ................................................... 44 2.3.3 Monotonic tests........................................................................... 45 2.3.4 Fatigue tests................................................................................ 45 2.3.5 Creep test on one prism of 300 × 300 × 510 mm ....................... 48 2.3.6 Pseudo-creep tests, first series.................................................... 48 2.3.7 Pseudo-creep tests, second series ............................................... 50 2.4 Comments................................................................................................ 52 Chapter 3 Collapse prediction and creep effects............................................................ 57 P.B. Lourenço & J. Pina-Henriques 3.1 Introduction ............................................................................................. 57 3.2 Short-term compression: failure analysis and collapse prediction using numerical simulations .................................................. 58 3.2.1 Experimental results................................................................... 58 3.2.2 Continuum model....................................................................... 59 3.2.3 Particle model............................................................................. 62 3.2.4 Discussion of the results............................................................. 63 3.3 Long-term compression: experimental assessment................................. 66 3.3.1 Tested specimens........................................................................ 66 3.3.2 Standard