Site-term analysis and site-specific ground-motion parameters prediction #br#
based on strong motion data
Chen Longwei1,2 Chen Yuxiang1,2 Yuan Xiaoming1,2
1. Institute of Engineering Mechanics, China Earthquake Administration, Harbin 150080, China;
2. Key Laboratory of Earthquake Engineering and Engineering Vibration, China Earthquake Administration, Harbin 150080, China
Abstract：The recently proposed site-term (δS2Ss) is a measure of the seismic response characteristics of a site. Through a systematic analysis of the different residual components by FA 2010 and BA 2008 GMPEs on a sizable set of 210 ground-motion data recorded at 20 stations in the 14 earthquake sequences of 2010 and 2012 in the Canterbury region of New Zealand, the site-terms of the selected stations are presented by the well-developed procedures of variability analysis of single-station records. The analytical results show that the site-term is solely interconnected with the prevailing geological conditions in the site but independent of GMPEs. The large site-term values potentially imply site amplification effects from model predictions using a simple site classification, while small values indicate possible site deamplification. When using the GMPEs based on global dataset to predict the ground motion parameters for a specific site, uncertainty will emerge and cause false prediction. The site-term can correct the predictions of GMPEs by taking into account of specific site properties. The corrected spectral values are more close to the observations than the predictions directly by GMPEs. The research results can provide reference for the PSHA calculation considering site effect and the prediction of site-specific ground motion.
