Risk Analysis of Bridges to Prioritize Post-Storm Scour Mitigation Plans

Bridge pier scour is the leading cause of bridge collapse in the United States. The risk of scour related failures increases in the wake of severe storms, such as those experienced in recent years. Enhancing the resiliency of the transportation network and its ability to withstand future major weather events is largely dependent on the efficacy of bridge scour mitigation programs. However, systematic treatment of bridge piers for scour mitigation is often beyond the scope of available state budgets. It is therefore highly desirable to develop algorithms to prioritize bridges requiring scour mitigation in a given region. In this study, a case study is presented for risk assessment conducted in the state of New York to determine the critical bridges in most need of initial mitigation program funding. A risk assessment tool was implemented to evaluate the risk associated with each bridge, and that of the community that uses the bridge. Risk was calculated based on hazard level, exposure and vulnerability levels. The risk assessment model was found to effectively prioritize bridge scour mitigation in the state.