Evaluation of NGA-West2 and Chinese Ground-Motion Prediction Equations for Developing Seismic Hazard Maps of Mainland China

摘要

Ground-motion prediction equations (GMPEs) are important elements in seismic hazard assessments. Here, we evaluate GMPEs from the Next Generation Attenuation-West2 (NGA-West2) project to confirm the applicability of those GMPEs to the China region and to assign relative weighting for each GMPE for use in developing probabilistic seismic hazard maps. We also examine the GMPEs used to develop the 2015 seismic ground-motion parameters zonation map of China; this set of GMPEs provides attenuation equations only for peak ground acceleration and velocity. We collect instrumental ground-motion data from past earthquakes that occurred in and near China, mostly from Chinese journal articles and the NGA-West2 project database. We compare the ground-motion data with ground-motion median curves of the GMPEs for various spectral accelerations and perform residual analysis with respect to magnitude and distance. The analysis results show that (1) for short ground-motion periods, the NGA-West2 relationships are generally consistent with the data and perform better than the GMPEs used to develop the 2015 seismic ground-motion parameters zonation map of China, and (2) for long ground-motion periods, the NGA-West2 relationships predict higher ground motion than the observed data. We then quantitatively rank the GMPEs using a log-likelihood (LLH) approach. Based on the LLH results, weights are assigned to the GMPEs to be applied in developing seismic hazard maps of China.