Seismic mitigation effect of shallow-covered underground frame station with rubber bearings

Based on the damage mechanism of shallow-covered underground frame structures and the local seismic mitigation design concept of reducing the horizontal deformation of center column, the applicability and effectiveness of rubber bearings in underground stations are discussed. Firstly, the seismic mitigation principle of the rubber bearings setting at the top of center column is expounded theoretically. And then the three-dimensional refined finite element model for the rubber bearings is established, and the seismic mitigation effects of laminated rubber bearing and lead rubber bearing in the subway station are compared by using the dynamic time history methods. Finally, the influences of horizontal stiffness of the rubber bearings on the seismic mitigation effect of the structural system are further studied. The numerical results indicate that the seismic mitigation structure installed with the rubber bearings changes the distribution of the lateral force and greatly reduces the seismic response of the center column. Compared with the LRB, LNR shows a better seismic mitigation effect. In addition, as the horizontal stiffness of LNR increases, the seismic mitigation effect of the center column gradually weakens, but it exerts a favorable control effect on the deformation of the rubber bearing and sidewall. Therefore, the seismic mitigation control of underground structures and the optimization of bearing performance can be realized by reasonably selecting the type and parameters of the rubber bearings.