Ground Motion Evaluation at the Rokko Bridge for the 2011 off the Pacific Coast of Tohoku Earthquake

Abstract

During the 2011 off the Pacific coast of Tohoku Earthquake, Rokko Bridge, Ibaraki Prefecture, Japan, suffered significant damage including loss of two piers and three spans. In this study, to evaluate ground motions at the damage site, temporary aftershock observation was conducted at the site. The evaluated site amplification and phase effects between the damage site and JMA Hokota site are very similar. It indicates that the observed ground motions at JMA Hokota site during the 2011 main shock can be regarded as the ground motion at the damage site.