Abstract
During the 2004 Mid Niigata Earthquake, there was large difference between the earthquake motion amplitudes at the K-NET station and the JMA station in Ojiya, Niigata prefecture. The damage to low-rise buildings around the sites was relatively little for such large strong motions. To find the cause of the amplitude difference and the damage level, we conduct earthquake response analyses of surface soil layers considering soil nonlinearity and then earthquake response analyses of building models. These analyses show that the difference of strong motions at the two sites mainly depends on the surface soil amplification within approximately 3 meters below the surface. And by earthquake response analyses of building models, we confirm that the analytical results account for the little damage to low-rise buildings in the earthquake.
