NEW ATTENUATION RELATIONSHIPS FOR PEAK GROUND ACCELERATION AND VELOCITY CONSIDERING EFFECTS OF FAULT TYPE AND SITE CONDITION

Abstract

New attenuation relationships for peak ground acceleration on soil and for peak ground velocity on stiff ground are developed based on the regression analysis of strong ground motion recordings from 21 Japan earthquakes. In the analysis, 856 data for peak ground acceleration and 394 data for peak ground velocity are used, including those recorded in the near-source area. In the study, the earthquakes are classified into three groups, i.e., crustal, inter-plate and intra-plate earthquakes, according to the fault type. The site effects are evaluated quantitatively, and the path effects are evaluated by using two types of distance measurements, such as fault distance and equivalent hypocentral distance. The new attenuation relationships show that an intra-plate earthquake generates stronger acceleration and velocity than inter-plate and crustal events. The results also show that the earthquake with deeper focal depth generates stronger ground motion.