A very new RC building with soft first story was collapsed by the 1995 Hyogoken-Nanbu earthquake. The nonlinear earthquake response analysis, where strength deterioration was considered in representing member nonlinearity, was conducted to simulate how the building behaved and eventually collapsed during the earthquake. The analysis was found to fairly well simulate the observed damage including residual displacement. It was also revealed that if the first story mechanism might occur, the collapse could be unavoidable even for the building with base shear strength as much as 60% of the total weight.
