Research On The Seismic Performance Of Subway Station Structure In Tianjin Soft Soil Area

The underground constructions of large cities once encounter earthquake, which willhave a significant impact on city development and national political stability. However, theresearch on seismic area of underground structure in our country is not enough maturely.Especially in soft soil area, where the situation is more complex. It is a hard problem to beresolved that how to ensure the underground structure under seismic action in soft soil areato keep safe and reliable. And yet there is not the relevant specification for seismic designof structures in Tianjin soft soil. Therefore, it is necessary to combine with undergroundengineering structure features and soil conditions to study the analysis theory and designmethod for structure on the soft soil in Tianjin.According to the actual engineering conditions of station Kunming Road station inTianjin subway, build the soft soil-station structure model based on ANSYS and use theviscoelastic artificial boundary. There is numerical analysis on the soft soil-stationstructure model under and the dynamic response of Tianjin seismic wave, Taft seismicwave and artificial seismic wave. And the research achievements will be applied in theengineering practice, provide some advice for structure seismic design in soft soil area ofTianjin. The main research results are as follows:(1)Consider on the interaction of soil-structure and simplify the underground structuresas three layer three span to establish the appropriate two-dimensional finite element model.And reach a conclusion on the vibration characteristics of the structural system by usingANSYS to conduct modal analysis.(2)Use viscoelastic artificial boundary to establish the two dimensional dynamicanalysis model of soil-structure interaction. There is numerical analysis on the softsoil-station structure model under and the dynamic response under seismic wave.Study onthe mechanical characteristics of structure under horizontal, vertical seismic wave andtwo-way coupling seismic response and this paper analyzed the damage parts and seismicweak link for structure under different seismic waves.(3)Conduct the time history analysis under the normal earthquake and the majorearthquake by three seismic waves. Under different loading conditions, analyse the internalforce and deformation to the main component, especially the center pillar. The result of thedeformation met the code for seismic design of buildings. The response of the structureunder Tianjin wave is the largest.(4)Study seismic response of the structure by changing structure stiffness, structuresurrounding soil distribution and buried depth for structure to design optimization for largeunderground space structure. The results show that the distribution of the soil is the keyfactors. With the improvement of structure surrounding soil, it can may effectively controlthe deformation and enhance the safety performance of the structure.