ANALYSIS ON AMPLIFICATION CHARACTERISTICS OF GROUND MOTION IN TOPOGRAPHIC IRREGULAR SITE SUBJECTED TO SPATIALLY VARYING INCIDENT WAVE

Abstract

The covariance response analysis method with the boundary element method has been developed considering the spatial variation of incident waves. The spatial variation is modeled with the exponential-decayed coherence function. The accuracy of the method is verified with the Monte Carlo simulation. The spatial variation of incident wave weakens the effect of irregular topography such as focusing and shadowing of ground motion. The effect of spatial variation of incident waves depend on frequency and the type of topographic irregularity. The soil amplification characteristics derived from the data observed by a vertical array at Kushiro J.M A site is adopted as a target of practical validation of the presented method. The results based on the presented method agree well with the target.