Seismic Response And Analysis Of Subway Station Based On Finite Element Method

At present,more and more cities are suffering from the "big city disease",and traffic congestion,environmental pollution and other problems are increasingly serious.Underground space development has become one of the effective ways to alleviate and solve the current urban development dilemma.Among them,subway has been concerned and recognized by people for its characteristics of safety,efficiency,convenience and greenness.However,earthquake disaster is extremely serious in our country.Once the subway station structure is destroyed by earthquake,it will cause unbearable losses to the society.Therefore,it is of great practical significance to study the seismic resistance of subway station structure.Based on the three-dimensional viscoelastic artificial boundary,a formula for calculating the input of multilayer ground motions is derived.The method takes into account the reflection and transmission of seismic waves on different soil surfaces and the effect of different soil materials on seismic wave velocities.The method was used to input ground motion in ABAQUS software through Python programming,and the feasibility of the method and the accuracy of the results were verified by a three-dimensional two-layer foundation model under the action of simple harmonics.This paper takes a subway station in Changsha city as the engineering background and uses ABAQUS finite element software to carry out three-dimensional numerical simulation.In this paper,the dynamic response of subway station under the action of seismic wave is analyzed,the stress and deformation damage characteristics are obtained,and the station meets the requirements of seismic code.This paper analyzes the influence of structural characteristics and site conditions on the seismic performance of the structure,studies the influence of different seismic measures on the seismic performance of subway stations,and draws the following conclusions:(1)Enhancing the strength of the central column or the whole structure material can effectively reduce the vertical deformation of the roof but cannot restrain the horizontal deformation of the station.(2)When the central column of the station structure adopts split type,its lateral displacement will increase by about 10%,but its shear force is reduced by nearly 30%,which can effectively avoid the failure of the central column due to insufficient ductility.(3)The circular section central column can reduce the horizontal deformation of the station to a small extent compared with the rectangular section central column,and the maximum equivalent plastic strain at the connection between the roof and the side wall is greatly reduced,which can effectively reduce the tensile damage of the side wall of the station.(4)Increasing the elastic modulus of surrounding soil can significantly reduce the horizontal deformation of the station structure,but will increase the vertical displacement of the roof.When strengthening the strength of surrounding soil,the vertical compressive capacity of the structure should be strengthened to avoid the compressive failure of the structure.(5)The lateral isolation layer composed of rubber granular soil in the subway station can effectively enhance the lateral deformation resistance of the station structure and improve the seismic performance.When the content of rubber particles is low(10%),the horizontal deformation of the structure is obviously controlled,and the horizontal displacement of the side wall is reduced by nearly 31%.When the content of rubber particles is large(30%),the elastic modulus of the isolation layer is low,and the constraint on the horizontal displacement of the side wall is not obvious,but the maximum axial force and shear force of the column are greatly reduced.Under the action of vibration isolation layer,the plastic damage disappears at the joint between roof and side wall,but with the increase of rubber particle content,the plastic damage will appear in a small range at the bottom of side wall.