Investigation On Seismic Performance Of A Subway Station With Aboveground Structure In Lanzhou

If an underground structure is damaged because of an earthquake there is an inherent difficulty and repairing will cause problems because of difficulty and high cost.Because the loess site has its special characteristics,such as large pores,weak cementation,columnar joints and other properties,the earthquake damage in the loess area is very serious.In recent years,with the accelerated development of underground space development and utilization in the loess region of central and western China,the number of subway projects is increasing.The relevant research carried out in China is mostly focused on the seismic response of underground structures under the geological conditions in the eastern region.Therefore,this paper takes a subway station house in lanzhou as the prototype and analyzes the seismic response characteristics of a subway station with aboveground structure under the loess site.The specific content of this paper is as follows:(1)The basic theory of soil-structure interaction,and the constitutive relation of the Mohr-Coulomb elastoplastic model selected in numerical simulation and the elastoplastic damage model of concrete were introduced.(2)The shaking table test of the underground station building with the aboveground structure in the loess site was carried out.The El-Centro wave,the Lanzhou artificial wave and the Taft wave were selected as the ground motion input,adjust the peak acceleration,set different working conditions,explored the influence of different spectral characteristics and different peak accelerations on the model system,made a clear analysis of the experimental macroscopic phenomena and test results,obtained the seismic response law of the model foundation soil and model structure.(3)Based on ABAQUS finite element analysis software,the finite element analysis model of loess free field was established.The input acceleration peak was 0.2g ground motion with different spectral characteristics.The displacement and acceleration amplification coefficient at different depths were analyzed,and the dynamic response law of free field was obtained.(4)Analyzed the numerical model of shaking table test for a subway station house with aboveground structure under the loess site,compared and analyzed the numerical results with the test results,and verified the reliability of the established numerical model of shaking table test.In summary,the shaking table test of the subway station structure with an aboveground structure in the loess site was carried out,and the numerical model of the shaking table test was established for comparison and verification with finite element analysis software.The research results are that it can provide reference for seismic design of the underground structure in loess area,which has practical research significance and application value.