Reliability assessment framework of deteriorating reinforced concrete bridges subjected to earthquake and pier scour

摘要

This study assesses the life-cycle probability of survival of a deteriorating reinforced concrete girder bridge subjected to earthquake and pier scour. Adopting a component level approach, the framework of reliability assessment of bridge is established for its service life. The framework is established by the following three steps: 1) establish the probabilistic models of natural hazards; 2) capture the responses of bridge subjected to multiple hazards using SAP2000; 3) utilize methods of time-dependent reliability to assess the probability of survival of the bridge during its service life. The result shows that comparing to the pier scour, deterioration affects the seismic fragility of the bridge more significantly; however, pier scour could lengthen the natural period of bridge, and reduce the seismic response of the bridge, when the scour depth is under a specific level. It would underestimate the effects of multi-hazard to consider the hazards individually, when the correlation of structural effects induced by multi-hazards is negative, and the effects could be overestimated when the correlation is positive. This study reveals the two types of the correlations for the seismic fragility analysis of the reinforced concrete bridge, which should be noticed when design and operate a bridge subjected to multi-hazard.