Statistical, Risk, and Reliability Analyses of Bridge Scour
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 140, Issue 2
Abstract
Bridge scour is the loss of soil by erosion because of water flowing around bridge supports. Scour has been the number one cause of bridge failure in the United States with an average annual rate of 22 bridges collapsing or being closed owing to severe deformation. This paper addresses three topics related to bridge scour. First, a set of databases was used to quantify the statistical parameters associated with the scatter between the predicted and measured pier scour depth, as well as the probability that a deterministically predicted pier scour depth will be exceeded. These databases also were used to provide the bias factors in current predictions. Secondly, these statistical parameters were used to develop a reliability-based load and resistance factor design for shallow and deep foundations subjected to scour. The goal was to provide a design procedure where the reliability of the foundation is the same with or without scour. Reliability only addresses the probability of success and, therefore, of failure. Finally, the discussion was broadened by using the concept of risk defined as the probability of failure times the value of the consequences. In this third part, the risk associated with bridge scour was quantified and compared to risks associated with other engineering structures. Target values of acceptable risk were recommended as part of the conclusions.
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Acknowledgments
This research work was funded by the funds of the Spencer J. Buchanan Chair at Texas A&M University. The authors also thank Dr. Vahid Bisadi at Texas A&M University, Winchell Auyeung and Mike Sullivan at the New York DOT, and Dr. Andrzej Nowak at the University of Nebraska, Lincoln, for their help and contributions to this work.
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Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 140 • Issue 2 • February 2014
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jul 11, 2012
Accepted: Jun 23, 2013
Published online: Jun 25, 2013
Published in print: Feb 1, 2014
Discussion open until: Apr 19, 2014
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