Site amplification of ground motion during the 1995 kobe earthquake and unsolved issue on sfsi problem

The deep basin-edge structure beneath Kobe City is a plausible cause for ground motion amplification in the damage belt during the 1995 Kobe earthquake. Strong motions were recorded at two neighboring sites, Takatori and Shin-Nagata, located in the western part of the damage belt. The latter site, which was the basement of a high-rise building, was less than half the amplitude observed at the former site. This difference has raised an issue related to the soil-foundation-structure interaction problem. The deep subsurface structures were not a direct cause of the spatial variation between the two sites. It appears that the strong, site-specific nonlinearity associated with the surrounding soil partially contributed to a large reduction of the foundation input motion.