Simplified Method for Time-Dependent Reliability Analysis of Aging Bridges Subjected to Nonstationary Loads

摘要

The performance of existing bridges may deteriorate in time due to aggressive environmental or operating conditions in service, which may eventually cause changes in structural resistance and reliability beyond the baseline assumed for new ones. In addition, the increasing trend of live loads applied to the bridges, which has been reported in many researches, also contributes to the reduction of structural reliability. In order to perform time-dependent reliability assessment for aging bridges subjected to nonstationary loading process with improved efficiency, a simplified method is proposed in this paper, where lower dimensional integral is involved in the calculation of reliability. With the proposed method, time-dependent reliability of a real aging RC bridge is conducted, and the effect of nonstationarity in load intensity on structural reliability is investigated. It is found that structural reliability is sensitive to the increase of load intensity, and is less sensitive to the varying mechanism of load intensity.