兵庫県南部地震で発生した強震域での加速度応答スペクトルの推定

Abstract

The 1995 Hyogo-ken Nanbu Earthquake have adopted the seismic intensity of JMA(Japan Meteorological Agency) scale 7 since The 1948 Fukui Earthquake. Although the response spectrum is one of tools to grasp the basic reasons of structural damage we could not calculate it in the severely damaged area by this earthquake because observed records of ground motions were not enough near source region. Therefore, we calculated theoretical acceleration response spectra at the ground surface in the region near the earthquake source based on the spectral moment method. To estimate earthquake motion on the ground surface the theoretical formula of earthquake motion at base rock level was derived. The amplification effect of the ground was introduced by using the multiple reflection theory. Theoretically estimated response spectra were modified by the response spectra calculated using observed earthquake motions.