Region Specific Consideration for GMPE Development, Representative Seismic Hazard Estimation and Rock Design Spectrum for Himalayan Region

Abstract

AbstractGround motion prediction equation (GMPE) is a major contributing component in establishing seismic hazard values, design coefficient, and risk level for disaster management in the region. Many seismic hazard analyses at a regional level are carried out using GMPEs developed elsewhere. In this study, realistic GMPE function form, suitable GMPEs with ranks and weights for different distance segments and the best design spectrum shape for the active region of the Himalayas is presented by analysis of regional recorded earthquake data. About 241 earthquake data recorded in rock sites in the Himalayan region has been collected and used here. The functional form of GMPE for the Himalayan region is selected by considering the mixed-effect analysis of the residual of the recorded and simulated ground motion. About 43 GMPEs applicable to the Himalayan region are used in the study, of which 12 were developed for the region. We have carried out a systematic analysis by Log-likelihood (LLH) method to test the applicability of the GMPEs for the Himalayan region using recorded earthquake data. Ranks and weights of applicable GMPEs are estimated for the segmented distance of <100 km, 100–300 km, and more than 300 km. These are helpful in seismic hazard analyses of different cities in North India. Further, we arrived at the design spectrum shape using bedrock recorded data through the Tripartite plot of acceleration, velocity, and displacement-control period and factors. It is noticed that the design spectrum shape arrived is different from the currently used design spectrum shape in the Indian seismic code. Based on regional data and study; there may be a need to reach a design spectrum shape for different soil classifications.KeywordsEarthquake dataGMPE form and selectionLog-likelihoodDesign spectrumHimalayan region