Flood fragility analysis for multiple failure modes of bridges by finite element system reliability analysis

Abstract

Flood fragility analysis has received less attention compared to seismic fragility analysis, even though flood is one of the major causes of bridge damage. Many aged bridges have collapsed with various failure modes due to flood-related causes, and this has prompted the requirement for performing reliability analysis in conjunction with sophisticated finite element analysis to obtain the accurate fragility curve of a bridge for various limit state functions. In the present study, finite element reliability analysis is applied to the flood fragility analysis of an old bridge in Korea. Different flood-related factors such as increased water velocity, scouring, and debris accumulation are used to take into consideration a variety of bridge failure modes such as excessive displacement, lack of ductility, and excessive stress.