Calibration of Seismic Input Parameter Based on Reliability and Fragility
Within the framework of Performance-Based Earthquake Engineering(PBEE)and classical reliability theory,this study re-views the common characteristics of seismic fragility and reliability,interpreting the theoretical foundation and probabilistic methods for their combination.In the case study,probabilistic engineering demand parameters and seismic fragility for a continuous girder bridge are first analyzed using non-linear dynamic time-history analysis.Then,three types of seismic performance objectives are con-sidered for the seismic design of the pier.Additionally,reliability analysis is conducted considering dead load and vehicle live load.Various seismic return periods are set to calculate target reliability indexes according to the Poisson random process.This process calib-rates the initial reliability index,which is then combined with the fragility curve using a probabilistic approach to determine seismic in-put parameters for different seismic performance objectives.The results show that the calibrated input parameters are 0.25 g,0.24 g,and 0.22 g for return periods of 1000,475,and 50 years,respectively.These values are slightly larger than the 0.21 g determined by the fra-gility curve alone.The proposed method simultaneously considers seismic fragility and reliability,providing a new approach for the seismic design of structures with varying seismic requirements.
万方数据
维普
