A Methodology for Assessing the Component-Level Fragility Curves and Its Application to a Class of Integral Abutment Bridges

Abstract

Seismic vulnerability assessment of structures is a major research area and the output, i.e., fragility curves (FCs), within a probabilistic framework, devises effective seismic disaster mitigation. The present study proposes a novel methodology for obtaining the structural component-level FC through two new approaches with respect to the assessment of seismic demand and the computation of fragility. The present study evolves an existing nonlinear static method by a few steps to be able to assess the probabilistic demands and develops a numerical computation technique that exploits the actual profiles of the evaluated distributions of the structural capacity and demand data in a study to obtain the fragility magnitudes. The substitute methodology is implemented to derive the FCs of a class of integral abutment bridges while assessing the demands in a simple manner and avoiding the complexities of dynamic analysis and yet with reliable precision as well as averting the misjudgment of fragilities stemming from the lognormal or normal fit on the data, which are practically very rough fit or misfit to it, as imposed in the traditional fragility formulation.