地震动衰减关系

Ground motions intensity measures (IMs) are typically estimated using probabilistic seismic hazard analyses (PSHA), which combine the effects of source, path, and site on the IM. Hazard analyses use attenuation relationships to define the probability density function (PDF) for IM conditioned on earthquake magnitude and site-source distance. These PDFs are log-normal, being defined by a median and standard deviation. When ground response analyses are performed to evaluate site effects in lieu of more approximate methods, it is with the expectation that the standard deviation would be reduced and any bias in the median would be removed. This study investigates the degree to which these benefits of ground response analyses are realized as a function of site condition, and outlines how ground response analyses can be implemented within PSHA.