Abstract

This study aims to clarify the damage mechanism of a long-period bridge system-the Ohkirihata Bridge damaged in the 2016 Kumamoto earthquake-subjected to the combined effects of long-period pulsive ground motions and surface fault displacements. The target bridge's site-specific waveforms at abutment A1 were estimated using the finite difference method. Linear dynamic analysis with a three-dimensional finite element model of the bridge structure-underground interconnected system was performed to examine the effects of longperiod pulsive ground motions on the coupled responses of essential structural components: superstructure, rubber bearings, abutments, piers, foundations and underground.