This proceedings volume contains 38 papers presented at the 4th Working Conference on "Rel iability· and Optimization of Structural Systems", held at the Technical University of Munich, Germany, September 11- 13, 1991. The Working Conference was organised by the IFIP (Interna tional Federation for Information Processing) Working Group 7.5 of Technical Committee 7 and was the fourth in a series, following similar conferences held at the University of Aalborg, Den mark, May 1987, at the Imperial College, London, UK, September 1988 and at the University of California, Berkeley, California, USA, March 1990. The Working Conference was attended by 54 participants from 16 countries. The objectives of Working Group 7.5 are: • to promote modern structural systems optimization and reliability theory, • to advance international cooperation in the field of structural system optimization and reliability theory, • to stimulate research, development and application of structural system optimization and reli ability theory, • to further the dissemination and exchange of information on reliability and optimization of structural systems • to encourage education in structural system optimization and reliability theory. At present the members of the Working Group are: A. H.-S. Ang, U.S.A. M. Grimmelt, FRG G. A ugwti, Italy N. C. Lind, Canada M. J. Baker, UK H. O. Mad&en, Denmark P. Bjerager, Norway R. E. Melcher~, Australia C. A. Cornell, U.S.A. F. Mo~e~, U.S.A.

Focussing on structural reliability methods, reliability-based optimization, structural system reliability and risk analysis, lifetime performance and various applications in civil engineering. Invaluable to all concerned with structural system reliability and optimization, especially students, engineers, and workers in research and development.

This proceedings volume contains papers presented at the Third Scientific Meeting of the IFIP Working Group on "Reliabilty and Optimization of Structural Systems". The contributions reflect recent developments in the field of modern structural systems optimization and reliability theory and point out directions for further research. Also perspectives for the education in this field were discussed.

This volume is an outcome of the 11th IFIP WG7.5 working conference on Reliability and Optimization of Structural Systems in Canada. The conference focuses on structural reliability methods and applications and engineering risk analysis and decision-making.

The need for a comprehensive book on probabilistic structural mechanics that brings together the many analytical and computational methods developed over the years and their applications in a wide spectrum of industries-from residential buildings to nuclear power plants, from bridges to pressure vessels, from steel structures to ceramic structures-became evident from the many discussions the editor had with practising engineers, researchers and professors. Because no single individual has the expertise to write a book with such a di.verse scope, a group of 39 authors from universities, research laboratories, and industries from six countries in three continents was invited to write 30 chapters covering the various aspects of probabilistic structural mechanics. The editor and the authors believe that this handbook will serve as a reference text to practicing engineers, teachers, students and researchers. It may also be used as a textbook for graduate-level courses in probabilistic structural mechanics. The editor wishes to thank the chapter authors for their contributions. This handbook would not have been a reality without their collaboration.

Our knowledge to model, design, analyse, maintain, manage and predict the life-cycle performance of infrastructure systems is continually growing. However, the complexity of these systems continues to increase and an integrated approach is necessary to understand the effect of technological, environmental, economic, social, and political interactions on the life-cycle performance of engineering infrastructure. In order to accomplish this, methods have to be developed to systematically analyse structure and infrastructure systems, and models have to be formulated for evaluating and comparing the risks and benefits associated with various alternatives. Civil engineers must maximize the life-cycle benefits of these systems to serve the needs of our society by selecting the best balance of the safety, economy, resilience and sustainability requirements despite imperfect information and knowledge. Within the context of this book, the necessary concepts are introduced and illustrated with applications to civil and marine structures. This book is intended for an audience of researchers and practitioners world‐wide with a background in civil and marine engineering, as well as people working in infrastructure maintenance, management, cost and optimization analysis. The chapters originally published as articles in Structure and Infrastructure Engineering.