Probabilistic seismic hazard analysis using reliability methods

Abstract

By considering uncertainties in the input parameters (e.g., magnitude, location, wave path, etc.), the Probabilistic Seismic Hazard Analysis (PSHA) aims to compute annual rate of various exceeding ground motions at a site or a map of sites of all anticipated given earthquakes. Uncertainties may be originated due to inherent randomness of the phenomena or variability in the mean values of different models parameters, mainly due to use of finite-sample size of observations. The first, in literature reviews, is commonly named aleatory uncertainty; the second is known as epistemic uncertainty. The total probability numerical integration, generally employed to calculate PSHA, only considers aleatory uncertainties, and variability in the models' parameters is neglected to simplify calculation. In this paper, as an alternative to the total probability numerical integration, matured and standard reliability methods tailored to effortlessly consider both types of uncertainties are put forward to compute site-specific PSHA. Then, as an application study, the peak ground acceleration hazard curve for the site, at which a historical bridge is located, is developed and compared with those obtained from the total probability numerical integration.