Study On Seismic Performance Of A Subway Station In Changsha

With the accelerating process of Chinese urbanization,subway transportation become increasing popular for its characteristics,including safety,convenience,large capacity,punctuality,etc.Thus,it gradually become one of the main transportation in cities.But there are less study related to earthquake resistance of Metro stations at home and abroad.Besides,there are no special standards for seismic design of metro station structures in China.Therefore,this paper is aimed to build a three-dimensional numerical analysis model for the main metro station structure and surrounding soil of the subway station in Changsha.The seismic response of the project under horizontal ground vibration is evaluated mainly from the mechanical indicators,which include vertical force of the floor,horizontal force of the side wall,time response value of the acceleration of the soil-station structure,internal force of the structure,and deformation,in order to guide the seismic design of this structure.First of all,the paper introduces the research related to seismic performance of underground station structures at home and abroad,explains the main significance of seismic research for Chinese underground station structures.Then,it introduces the seismic analysis method of the current underground subway station structure.Finally,the paper points out the key analysis points.In this paper,the experiment of scale shaking table of a subway station is adopted as an example to build a finite element numerical model.Through the software ABAQUS,scale test model is calibrated according to the parameters such as reasonable material constitutive model,contact condition,and artificial boundary condition.By comparing the acceleration time curve and the displacement time curve,it shows that the two curves are in good agreement,and the correctness of the model is verified.Then the stress,vertical displacement of floor and horizontal displacement of side wall of station are also analyzed through the numerical model.The results show that the viscoelastic boundary can accurately simulate the interaction between soil and structure,and the error between the simulation results and the test results is small.The paper carries out seismic analysis of the actual project for the subway station in Changsha.Firstly,it introduces geological conditions of the project and the requirements for seismic fortification,and then establishes a numerical model.Fiveseismic waves are selected according to the principle of selection wave of seismic standard,and the nonlinear dynamic time-history analysis of the project is carried out.The results are mainly explained by mechanical indexes,including vertical displacement,lateral wall horizontal displacement,acceleration time-histories analysis,internal force analysis and stress of the main structure.The analysis results show that in the five seismic waves,the seismic wave action intensity of the artificial seismic wave is the largest,the yield order of each component in the main structure is obvious,and the fortification requirements of "big earthquake cannot fall" are satisfied.Finally,some design suggestions are proposed for the more seriously damaged parts.Finally,this paper summarizes the contents of the research,gives an outlook on the seismic research of underground structures,and puts forward some opinions on the future research.