Site-dependent design input ground motion estimations for the Taipei area: a probabilistic approach

Design seismic forces depend on the peak ground acceleration (PGA) and on the shape of design spectrum curves dictated in building codes. At present there is no doubt that it is necessary to construct so-called “site and region-specific” design input ground motions reflecting influence from different magnitude events at different distances that may occur during a specified time period. A unified approach to ground motion parameters estimation is described. A collection of ground motion recordings of small to moderate (3.0–3.5≤ML≤6.5) earthquakes obtained during the execution of the Taiwan Strong Motion Instrumentation Program (TSMIP) since 1991 was used to study source scaling model, attenuation relations and site effects in Taiwan region. A stochastic simulation technique was applied to predict PGA and response spectra for the Taipei basin. “Site and region-dependent” uniform hazard response spectra were estimated for various geological conditions in the Taipei basin using a technique of probabilistic seismic hazard analysis.