Uncertainty Analysis of Bridge Pier Scour Depth

Abstract Submission: Bridge failures due to pier scours are relatively common and are a significant concern for civil engineers. Based on literature, a substantial percentage of bridge failures are attributed to scour. In the United States, scour is responsible for about 60% of bridge failures. Similar trends are observed worldwide, with many countries reporting scour as a leading cause of bridge collapses.

A bridge failure may cause loss of life, property, and other losses such as associated economic and social impacts, etc. Bridge scours are one of several other causes of bridge failure. A number of empirical equations have been developed for scour depth at bridge piers using laboratory and field tests and making simplified assumptions. For a given dataset, application of different methods gives significantly different estimates of pier scour depths. This creates ambiguity concerning structural safety, stability, cost estimates, and reliability of bridges. In this paper, uncertainty in pier scour depth will be investigated due to differing methodologies, natural variations in river flow, sediment transport, particle size distribution with respect to flow depth, and weather conditions. It is hoped, this study may help understanding and mitigating some pier scour issues causing bridge failure and offer some enhancement of bridge design and maintenance methods to increase the resilience and safety of bridge infrastructure.

Learning Objectives/Expected Outcome (Optional) : Key Words: Bridge failure, stability and safety, pier scour, ambiguity, and uncertainty analysis