Response to discussion of “Seismic assessment of deep water bridges in reservoir considering hydrodynamic effects using endurance time analysis”

Abstract

Discussers (Hariri-Ardebili and Sattar) address the paper “Seismic assessment of deep water bridges in reservoir considering hydrodynamic effects using endurance time analysis” written by the coauthors of this response. They present the fundamental assumptions on the generation of Endurance Time Excitation Functions (ETEFs) and the derivation of fragility functions by Endurance Time Analysis (ETA). Since the fragility functions of bridge piers derived in the discussed paper are based on a deterministic fragility dispersion ζ, discussers criticize that the record-to-record variability βRTR of ground motions and fragility dispersion ζ cannot be captured by ETA, which can be affected by many factors (e.g. damage states, Intensity Measures (IMs) and levels of Engineering Demand Parameters (EDPs)), and, consequently, consider it inappropriate for deriving the fragility curves by assuming a constant ζ. The discussers also provide a probabilistic ETEF approach to estimate the βRTR. Coauthors appreciate the discussions on the determination of the fragility dispersion ζ for ETA-based fragility analysis and welcome the new approach to estimate fragility dispersions for ETA but disagree with the discussers’ characterization of fragility dispersions and consider that it is appropriate to develop the ETA-based fragility curves by assuming a constant ζ for a specified type of structures as presented in the discussed paper.