Numerical analysis on the seismic performance of subway station reinforced by ECC-BFRP

In areas with high seismic activity, enhancing the seismic performance of subway station structures is of paramount importance. This paper presents a novel approach involving the application of an ECC-BFRP (Engineered Cementitious Composite with Basalt Fiber Reinforced Polymer) composite layer to reinforce central columns of subway stations situated in loess site. To evaluate the effectiveness of this reinforcement method, a three-dimensional finite element model of subway station structure, accounting for soil-structure interaction (SSI) effects, was meticulously developed using the finite element software Abaqus. The seismic responses of the subway stations with various reinforcement scenarios such as reinforced by the cement mortar, ECC, Mortar-BFRP and ECC-BFRP layer were respectively analyzed in comparison to the unreinforced station. Both the structural displacement response and the changing pattern of damage development for the overall and local structural members were obtained. The results indicated that the ECC-BFRP composite layer could effectively improve the stiffness of the central column and reduce the seismic response of the station. Meanwhile, the seismic damage of the central column was significantly reduced, and the seismic damage distribution of other structural members was uniformly distributed. Consequently, the seismic performance of the station was effectively improved. The research results provided valuable guidance for the seismic design of underground structures.