Impact of partially non‐ergodic site‐specific probabilistic seismic hazard on risk assessment of single buildings
Mohsen Kohrangi, Sreeram Reddy Kotha, Paolo Bazzurro
Abstract
The growth of global ground‐motion databases has allowed generation of non‐ergodic ground‐motion prediction equations (GMPEs) based on specific on‐site recordings. Several studies have investigated the differences between the hazard estimates from ergodic versus non‐ergodic GMPEs. Here instead we focus on the impact of non‐ergodic PSHA estimates on the seismic risk of nonlinear single‐degree‐of‐freedom systems representing ductile structures and compare it with the traditional risk estimates obtained using ergodic GMPEs. The structure‐and‐site‐specific risk estimates depend not only on the difference in the hazard estimates but also on the different hazard‐consistent ground‐motion record selection that informs the response calculation. The more accurate structure‐and‐site‐specific non‐ergodic risk estimates show that traditional ones may be biased in a way impossible to predict a priori. Hence, the use of the non‐ergodic approach is recommended, whenever possible. However, further advancements of non‐ergodic GMPEs are necessary before being routinely utilized in real‐life risk assessment applications.