Wolfgang Fellin, Heimo Lessmann, Michael Oberguggenberger & Robert Vieider, Analyzing Uncertainty in Civil Engineering

This volume comprehensively addresses the issue of uncertainty in civil engineering, from design to construction. Current engineering practice often leaves uncertainty issues aside, despite the fact that new scientific tools have been developed in the past decades that allow a rational description of uncertainties of all kinds, from model uncertainty to data uncertainty. It is the aim of this volume to take a critical look at current engineering risk concepts in order to raise awareness of uncertainty in numerical computations, shortcomings of a strictly probabilistic safety concept, geotechnical models of failure and their construction implications, actual construction, and legal responsibility. In addition, a number of the new procedures for modelling uncertainty are explained. The book is a result of a collaborate effort of mathematicians, engineers and construction managers who met regularly in a post-graduate seminar at the University of Innsbruck during the past years.

The book is the result of a collaborate effort of mathematicians, engineers and construction managers who met regularly in a post graduate seminar at the University of Innsbruck during the past years. It contains contributions that shed light on the central theme outlined above from various perspectives and thus subsumes the state of discussion arrived at by the participants over those years. Except for three reprints of foundational papers, all contributions are new and have been written for the purpose of this collection.

The book starts with three papers on geotechnics. The first two articles by Fellin address the problem of assessment of soil parameters and the ambiguity of safety definition in geotechnics. The third paper by Oberguggenberger and Fellin demonstrates the high sensitivity of the failure probability on the choice of input distribution. This sets the stage for the theoretically oriented paper by Oberguggenberger providing a survey of available models of uncertainty and how they can be implemented in numerical computations. The mathematical foundations are complemented by the following paper of Fetz describing how the joint uncertainty in multi-parameter models can be incorporated. Next, Ostermann addresses the issue of sensitivity analysis and how it is performed numerically. This is followed by a reprint of a paper by Herle discussing the result of benchmark studies. Predictions of deformations obtained by different geotechnicians and numerical methods in the same problem are seen to deviate dramatically from each other. Lehar et al. present an ultimate load analysis of pile-supported buried pipelines, showing the extensive interplay between modelling, laboratory testing and numerical analysis which is necessary to arrive at a conclusive description of the performance of the pipes. The paper by Lessmann and Vieider turns to the implications of the geotechnical model uncertainty to construction management. It discusses the type of information the construction manager would need as well as the question of responsibility in face of large model uncertainties. The following paper by Oberguggenberger and Russo compares various uncertainty models (probability, fuzzy sets, stochastic processes) at the hand of the simple example of an elastically bedded beam, while the article by Oberguggenberger on queueing models ventures into a similar comparison of methods in a theme relevant for project planning. The book is completed by a reprint of a survey article showing how fuzzy sets can be used to describe uncertainty throughout
civil engineering.