Effects of modelling uncertainty on the seismic fragility of frame piers in double-deck viaducts

Abstract

Frame piers of double-deck viaducts (DVFP) have been widely studied and applied due to their high levels of space utilisation and significant engineering benefits, but the uncertainty of their information on modelling significantly affects the accuracy of calculation results for structural seismic demand and seismic capacity, which leads to challenges regarding the accuracy and reliability of seismic fragility analysis. In this paper, an accurate non-linear finite element model of DVFPs was established based on the OpenSees open platform. The seismic fragility analysis of DVFPs is carried out by introducing the endurance time method, and the tornado diagram and central point methods were performed to investigate the sensitivity and uncertainty of a seismic fragility of DVFPs to nine modelling parameters, respectively. The results show that the logarithmic standard deviation of fragility when slight damage, moderate damage, significant damage, and collapse occur on DVFP after considering modelling uncertainty will increase by 6.4%, 16.1%, 13.3%, and 20.1%, respectively. Therefore, it is necessary to consider the influence of modelling uncertainty in seismic fragility analysis.