The damage to Daikai subway station in Kobe city

Japan during 1995 Kobe earthquake is analyzed in detail. The earthquake responses of Daikai subway station under bedrock ground motion in horizontal and vertical direction are analyzed respectively by the 2-D substructure subtraction method modeled by software SASSI2000. The effect of soil-structure dynamic interaction and soil nonlinear dynamic property on the earthquake responses of Daikai subway station are considered

where Soil nonlinear dynamic property is describe by equivalent linearization model and the dynamic performance parameters of soil layers are obtained by software SHAKE91. The soils above the subway station are considered as an affiliated structure of the subway station. The nephograms of all kinds of stress induced by earthquake ground motion are drawn. Analyzing on the nephograms proves that the collapse of the columns in Daikai subway station were induced by both of the horizontal and vertical vibrations. All kinds of damage caused by the 1995 Kobe earthquake can be explained well by nephograms drawn in this paper.