Analyse on seismic performance of complex underground space structure under rare earthquakes

The seismic design of underground structures is still dominated by two-dimensional model calculation, but for complex underground space structures, it is hard to reflect the real characteristics of the structure, and it may have certain errors in the calculation. The three-dimensional dynamic time history analysis method can calculate the deformation and internal force state of the structure at each time in seismic response, and provide a more realistic dynamic characteristic of the response structure. The key modeling processes, such as viscoelastic boundary conditions, the input of ground motion parameters method, and structural damage evaluation indicators, were summarized. Taking the underground space structure of the financial island supporting municipal engineering in Xiong’an New Area as an example, and the seismic performance of the underground space of the financial island under the action of a rare (E3) earthquake was analyzed by GFE finite element analysis software. The results show that the elastic-plastic interlayer displacement angle index of the structure under rare earthquake meets the requirements of the code limit of 1/250, and the main structure has not suffered extensive damage, only the vertical components in weak parts, such as local floor openings, are damaged. It provides a reference for similar engineering designs.