Seismic Performance Study On Subway Station With Two Floors On The Ground Built In Loess Area

The phenomenon of earthquake damage in the loess area differs from that of other common soil texture due to the particularity of soil structure for the loess itself.More cities in the west of China are located in loess area.With economic development of the west area,expansion of urban scale,the traffic environment of some major cities of the west area deteriorates apparently.In order to relieve the traffic jam for these cities,metro starts to enter the west loess area for metro is a kind of effective way to relieve urban traffic pressure.While the special geological conditions in the aseismic design methods given in The Earthquake Resistant Design Code for the Structure of Urban Railway System(GB50909-2014)which is the existing technical code of our country has not been considered.Although some researches have been made on earthquake resistance for the metro structure in the loess area,and some achievements has been made,the previous research modes were governed by numerical simulation with less shaking table test.Only underground structure has been researched in the completed shaking table test for the railway stations in the loess area,while numerical analysis or shaking table test has not been made on the railway stations with both overground and underground structure.With enhancement of utilization of underground space in cities,there has been more and more architectures with both overground and underground structure most of which belong to public service facilities with compact population,consequently once serious earthquake damage occurs in earthquake,immeasurable loss will come.Therefore,the article investigated the anti-seismic property of overgroundstructure in the loess area the results can be used to provide certain theoretical data and relative data reference for anti-seismic property design for underground architecture structure,underground commercial streets and air-raid shelters in the loess area.The article mainly covers the following parts:(1)This paper reviews the development of seismic research on subway underground structures,summarizes the damage forms and damage characteristics of subway stations underground structures under seismic action,and the research methods for the seismic behavior of underground subway structures.It also analyzes the research status of subway underground structures in the loess area,and draws the research content of the paper.(2)The similarity design of shaking table model test was completed with artificial quality model in accordance with Bockingham ? theorem.The scale model manufacture was completed according to similarity relation to determine test plan.(3)The project firstly conducted the research on shaking table test with the seismic performance of overground structure in the loess area.And the dynamic response rules of model loess foundation and model structure and the failure characteristics of the structures in earthquake effect were achieved by the result analysis of shaking table test.(4)The software ABAQUS of finite element analysis was used to conduct the numerical analysis for underground parts of the prototype structure.And the dynamic response difference of model foundation for overground structures and non-overground structures was analyzed respectively by comparing with the results of shaking table test.Additionally,the parts easily to be damaged of metro station structure in the loess area in earthquake effect were presented by the analysis of malformation and stress response of model structure,so as to provide reference for aseismatic structure design for metro station structure in the loess area.