Conditional hazard for simplified multi‐site seismic hazard and risk analyses

Abstract The joint probability distribution of different intensity measures at sites in one earthquake is needed to define the stochastic process regulating exceedance (in time) ensemble sites, which turn a funding element so‐called multi‐site probabilistic seismic hazard analysis (MSPSHA). simplest model for event requires mean vector and covariance matrix all conditional magnitude location earthquake, may need large amount data be calibrated. (CH) approach, originally developed single‐site surrogate vector‐valued analysis, simplified option MSPSHA, as it explicitly models only part while rest forcefully follows working assumptions. presented paper compares CH approach MSPSHA against benchmark complete modelled, using testbed one‐hundred are considered. When comparison metric given number exceedances observed some time intervals, found that viable alternative although degree approximation sensitive how many considered (e.g., spectral acceleration). taken way risk, considering fragilities portfolio hypothetical buildings, taking observing structural failures interval, introduced by with respect further reduced.