脈動観測による上海平野の地盤震動特性-スペクトル比(H/V)のピーク周波数と基盤岩深度との関係-

Abstract

Under the context of IDNDR, a project entitled "Seismic Risk Assessment of Urban Facilities in A Sedimentary Region Affected by River Route Changes" was conducted by DPRI, Kyoto University and State Laboratory for Disaster Reduction in Civil Engineering, Tongji University, China. The subjects include microzonation of the Shanghai region based on microseism observations. Brief reports were given for microseism observations, geological setting of the Shanghai plain, basic characteristics of microseisms at various soil sites and a reference rock site. To evaluate ground vibrational characteristics, spectral ratios of horizontal components to vertical ones, H/V, were examined. All the H/Vs had sharp peaks, which varied with site location. A linear relation between peak periods of H/V and the depth to bedrock was obtained. Applicability of H/V to microzoning of sedimentary regions was discussed.