Strong motion estimation at Iwakiri Railway Bridge for the 2011 off the Pacific coast of Tohoku Earthquake based on a super asperity model considering empirical site amplification and phase effects

Abstract

During the 2011 off the Pacific coast of Tohoku Earthquake, Iwakiri Railway Bridge, Sendai City, Miyagi Prefecture, Japan, suffered significant damage. In order to analyze the damage mechanism, it is important to evaluate strong ground motions at the bridge site with high accuracy, taking into account site effects. In this study, strong ground motions at the bridge site were estimated based on a super asperity model considering empirical site amplification and phase effects. The same approach was also applied to estimate ground motions at strong motion stations surrounding the bridge site to confirm its applicability for the 2011 main shock. Site effects at the application sites were evaluated based on the records of temporary aftershock observation. The estimated ground motions will be useful in the detailed study of the failure mechanism of the bridge.