Numerical Simulation of the Seismic Damage of Daikai Station Based on Pushover Analyses

Abstract

Numerical analysis is an important method for the study of seismic performance of underground structures. Current research on the seismic damage of Daikai station and the subway tunnel during the Great Hanshin earthquake mainly focuses on the dynamic time-history analysis. However, the modeling process of the dynamic time-history analysis is complicated and shows the characteristics of the enormous calculation amount, long running time and low computation efficiency. This paper briefly introduces the seismic phenomena of Daikai station and the subway tunnel during the Great Hanshin earthquake. The internal forces of Daikai station and the subway tunnel under horizontal and vertical bi-directional seismic effects are obtained by simplified seismic analysis. The pushover analyses of the columns are carried out to obtain the seismic performance curves of the columns under different vertical pressures by considering various loading and restraint conditions. Finally, the pushover analyses of the soil-structure system are carried out to reproduce the seismic damage of Daikai station and subway tunnel under horizontal and vertical bi-directional seismic effects. The results show that the computed damage is similar to the actual damage. The pushover analysis method, which considers both horizontal and vertical inertia forces of the soil, can be used to simulate the damage and study the collapse mechanism at Daikai station. Compared with the dynamic analysis, the calculation efficiency of the pushover analysis method is significantly higher; it is therefore suggested to use pushover analysis in seismic analysis of underground stations.

Keywords

• underground structures
• Daikai station
• pushover analysis
• vertical earthquake effect
• RC column
• CFST