# Hybrid Simulation of Seismic Responses of a Typical Station with a Reinforced Concrete Column
## 1 Introduction  
Serious damages of subway stations and tunnels were observed in the Kobe earthquake, indicating that underground structures were vulnerable under severe earthquake excitations [1]. The Daikai station was the first large-scale underground structure that almost collapsed in the earthquake. Therefore, researchers all around the world gave their explanations about the damage process of the Daikai station, both numerically and experimentally. Such investigations shed light on the damage process and the failure mode of the Daikai station [2]. Actually, a consensus on the seismic responses of a typical subway station has not been reached. Investigations on the damage process of a typical subway station require more work. Therefore, innovate numerical methods and experimental methods should be proposed to study the dynamic responses of a typical subway station. Generally, two kinds of methods, namely numerical methods and experimental methods, are developed to study the seismic behavior of subway stations. With respect to numerical modelling, the finite element method is widely used in time-history analysis. The nonlinear mechanical behavior of the underground structure, adjacent geotechnical media, and soil-structure interaction could be considered in time-history analysis. The propagation process of seismic waves in the infinite region would be reproduced with a reasonable boundary. Therefore, up to now, numerical analysis is themain way to study the seismic performance of subway stations, especially for failure progress [3; 4; 5; 6; 7]. Such investigations give clues to the design of typical underground structures. [PERSON] et al. [3] used the equivalent linearized constitutive model for soil modeling. The viscous boundary was selected at the bottom of the finite element (FE) model. The transmission boundary was selected laterally. The rigid beam element and elastic beam element were selected for the structure modelling. The results showed that the shear force of the center column reached the bearing capacity during the earthquake and brittle failure happened. Due to the damage of the concrete, the vertical bearing capacity of the central column decreased, and the thrust exceeded the bearing capacity, which caused the center column to fail. The upper end of the side walls and the upper roof reached the ultimate bending capacity after the center column crushed. [PERSON] et al. [4] applied an equivalent linearized constitutive material for soil modelling. The rigid boundary was applied on the bottom side, and the free boundary was selected on the lateral sides. The results showed that the soil-structure stiffness ratio was significant in the seismic analysis. The station with a lower stiffness ratio suffered more severe damage. As the Daikai station was designed subject to static loading only, the stirrup reinforcement ratio was relatively low, and brittle failure occurred due to the insufficient shear capacity. After the shear failure, the compressive bearing capacity of the central column decreased. In fact, the Daikai station had a large span. After the center column failed, the entire station collapsed due to the increased thrust of the central column. [PERSON] et al. [5] proposed a simplified approach to consider the nonlinear behavior of the station with FLAC-2D. The nonlinear constitutive models were applied to consider the nonlinear interaction between the soil and structure accurately. Based on the proposed framework, the failure process of the Daikai station can be traced by the dynamic time-history analysis. In order to decrease the seismic responses of the Daikai station, [PERSON] et al. [6; 7] proposed a self-centering energy dissipation column for the Daikai station. 3D time-history analysis results showed that the self-centering energy dissipation column would effectively decrease the internal forces of the central column and the peak and residual drift. To be specific, the drift would be reduced by 4-5%.