Study on the Reliability-based Design Method for Scoured Bridges

There are many reasons that make crossing bridge failure, Domestic and international studies have pointed out that one of the main reasons is scour event. In the existing bridge design codes, the scour effect is not considered as a load effect. When considering multiple-hazard reliability design, engineers will face the problem with load and resistance factor design which didn''t consider scour effect as a load. This study offer a creative thinking that transfer the scour effect into load pattern and put in load combinations, obtain a more direct method of design. The research team continues the previous results, start from the concept of equivalent scour load. We purposed two applications of equivalent scour load, one is build the scour fragility curve, the other is calculate the load factors of multiple-hazard load and resistance factor design. The objective is to help engineers to evaluate and design crossing bridge with scour event. Using Monte Carlo method to simulate hazard, and evaluate the bridge failure probability with the conditional probability. Finally we can get scour fragility curve. To calculate the load factors in multiple-hazard load and resistance factor design by reliability analysis. After develop scour fragility curve, engineers can quickly obtain the failure probability by scour depth. The load factor of multiple-hazard load and resistance factor design will be used in design crossing bridge, which make design procedure smoother.