Ground motion prediction equation for the Kathmandu Valley, Nepal based on strong motion records during the 2015 Gorkha Nepal earthquake sequence
Takuho Mori, Michiko Shigefuji, Subeg Bijukchhen, Tatsuo Kanno, Nobuo Takai
Abstract
Single-site ground motion prediction equations (GMPEs) for the acceleration response spectra of each site in the Kathmandu Valley was constructed using strong motion records of magnitude 5.0 through 7.3 the 2015 Gorkha Nepal earthquake aftershocks observed at eight sites in the Kathmandu Valley. The regression coefficient for the site term has a strong correlation with the bedrock depth at each site in the Kathmandu Valley. Therefore, a new GMPE applicable to the whole Kathmandu Valley in the long-period range of 1–10 s was generalized using the bedrock depth as a parameter. We applied this GMPE to the largest aftershock. Consequently, at each sedimentary station, the residuals of the predicted value by GMPE are smaller than those predicted by the existing GMPE, and the peaks of the observed response spectra are reproduced well.