Seismic performance of underground subway station with sliding between column and longitudinal beam

摘要

Existing studies on earthquake damage have shown that the center column of a shallow-covered underground structure is more prone to be damaged by a strong earthquake than other parts, as seen by the damage induced during the Kobe earthquake in 1995. In this study, in regard to the seismic damage process of an underground structure, elastic sliding base-isolated bearings are installed on the top of its columns. It is found that the seismic damage to the center columns and the medium plate of the underground structure is effectively alleviated by the sliding bearing. Consequently, the axial stress responses of the center columns are remarkably reduced and completely in a compressive state during a strong earthquake, which can effectively improve the overall seismic performance of the underground station structure. However, the mechanical transfer properties between a column and a longitudinal beam are also significantly changed by the elastic sliding bearings. Thus, the seismic damage to the slabs near the side walls of the underground structure is slightly aggravated following the elastic sliding bearing installation on the top of the columns.