Seismic fragility curve development by coupling FERUM and ZEUS-NL

Abstract

Accurate seismic fragility curve has been recognized as a key to effective seismic risk assessment and management. Existing methodologies for seismic fragility curve development can be classified into four groups: empirical, judgmental, analytical, and hybrid. Among them, analytical fragility curves are most widely used, and they can be categorized again into two subgroups, depending on whether one is using an analytical function or a simulation technique. Although the both types have shown decent performances in many seismic fragility problems, they often over-simplify the given problems in reliability analysis or structural analysis due to their own assumptions. In this paper, a new methodology for seismic fragility curve development is proposed. By coupling sophisticated software packages of reliability analysis (FERUM) and structural analysis (ZEUS-NL), the methodology enables us to obtain more accurate seismic fragility curves for less computational cost. In addition, it provides not only component probabilities, but also useful byproducts that allow us to perform the fragility analysis at system level. The proposed methodology is applied to a numerical example of a 2D frame structure and the results are compared with those by Monte Carlo simulation, demonstrating that the method derives seismic fragility curves accurately and efficiently.