Seismic Shaking Table Test And Numerical Simulation Analysis Of Model Structure Of Pillarless Large-span Metro Station

The pillarless large-span underground subway station is gradually becoming one of the main selections of metro stations because of its beautiful appearance and wide spatial view.However,there is still little research on the seismic performance of soil-structure interactions considering such subway stations.To this end,this paper takes the two stations of Nanning Metro as the engineering background,and uses the methods of shaking table test and numerical simulation to study the seismic response of the rectangular and arch-shaped pillarless metro station model structures considering soil-structure interaction.law.The specific work is as follows:(1)Based on the actual engineering of two stations in Nanning Metro,based on the similarity principle of the model,considering the interaction between the soil-station structure and the simulated seismic shaking table test system,a rectangle with a geometric similarity ratio of 1/50 is designed.The experimental model of the large-span metro station and the experimental model of an arch-shaped pillarless large-span metro station with a geometric similarity ratio of 1/80.According to the actual engineering data,the similarity of the soil cycle is taken as the main control index,the relevant performance test of the soil is carried out,the ratio of the test soil is determined,the reasonable model box is selected,and the test soil is carried out with this ratio.The preparation and optimization of the number and position of the sensors in the test soil and station model were carried out.Two test models of the soil-rectangular structure and the test soil-arch structure were tested and cured.The actual situation of the prototype soil-station structure.(2)Based on the background engineering survey report,two natural seismic waves and artificial seismic waves satisfying the original site characteristics were selected,and various horizontal directions were applied to the experimental soil-rectangular station model and the experimental soil-arched station model.The simulated seismic shaking table test under seismic excitation studies the seismic response characteristics of the experimental soil-two structural station model considering soil-structure interaction under horizontal seismic excitation,and summarizes the corresponding seismic response law.The results show that under normal conditions,the peak acceleration response of the test soil increases gradually from bottom to top under seismic excitation,and the peak acceleration response of the two structural station models is the largest in the top plate,the middle plate is the second,and the bottom plate is the smallest;The interaction of the test model of the soil-rectangular structure is the largest at the bottom plate,the second at the middle plate,and the lowest at the top plate.The interaction between the test model of the test soil-arch structure is that the bottom plate is larger than thetop plate.(3)Using ABAQUS numerical simulation analysis software,according to the relevant parameters obtained by the test soil shear test and compression test,select the reasonable soil,concrete constitutive model and the contact mode of soil and station model to test the soil-rectangular structure form and test.Based on the shaking table test of the soil-arch structure station model,the corresponding numerical simulation analysis model was established.The simulation analysis under various working conditions was carried out,and the results were compared with the shaking table test results.The results show that the results of numerical simulation analysis are in good agreement with the results of the shaking table test.The numerical simulation analysis model of the test soil-rectangular structure used in the paper and the numerical simulation analysis model of the experimental soil-arch structure are simulated.The result is reliable.In this paper,the numerical simulation analysis of the displacement response and weak parts of the two structural station models is also carried out.The results show that the displacement response of the station model and the arch model in the form of the rectangular structure is reduced from the top of the model to the bottom of the model under seismic excitation The weak position of the stress model in the rectangular structure of the station model under the earthquake excitation is the side wall.The top plate,the top plate at the top,the side wall-middle plate,the side wall-floor,and the bottom plate are twisted;the weak position where the stress is concentrated under the earthquake excitation is the side wall-top plate and side The wall-medium plate and the middle plate are twisted,and the bottom plate is twisted.These weak parts should attract the attention of designers.