Seismic Performance Analysis Of The Expanded Metro Station Under Shield Running Tunnel

In the future subway construction,some special locations may not have conditions to construct the station.In order to facilitate the movement of passengers,the lication where has conditions to open to public but has no conditions for the construction of metro station is in need of satisfying traffic operation at first.When the time is right,it is possible to expand the construction of metro station.Therefore,the construction of new lines in the future may be encountered in the operation of the expanded metro station under shield running tunnel.To solve this problem,the research group has done a lot of research work.The purpose of this paper is to research the seismic performance of a new type of subway station,which is formed by the extension of the shield section under the condition of moving train.In this paper,numerical simulations were carried out by using MIDAS GTS software,for the island platform structure scheme(7 meters shield diameter),island platform structure scheme(8.1 meters shield diameter)and side platform structure scheme(11.3 meters shield diameter),the response displacement method,response acceleration method and time history analysis method were used for the seismic performance analysis of the three kinds of expanded metro station,checking whether it can meet the seismic requirements,providing technical reference for seismic design of the project of the expanded metro station under shield running tunnel.In the same time,the paper made a comparison of the difference in calculation results of three calculation methods.Results show:1.At the same station structure,under the action of earthquake load,the internal force value of the shield segment and cross channel connection and the side wall of the station is larger than that of the standard load combination.According to the results of the three methods,the bending moment increases about 67%,the axial force increases about 33%and the shear value increases about 51%.Therefore,in the design of this type of station,the structural reinforcement need to consider the impact of seismic load.2.Three kinds of station structure scheme,under the same earthquake wave,calculation results of response acceleration method and response displacement method shows that the scheme of island platform(7 meters shield diameter)has better seismic performance,time history analysis results show that the scheme of island platform(8.1 meters shield diameter)has better seismic performance.Based on the three methods,the paper thinks that the scheme of island platform(7 meters shield diameter)is better.From the point of view of seismic design,it is more advantageous for the seismic design to select the scheme of island platform(7 meters shield diameter).3.Using three kinds of seismic design method for seismic performance calculation of three station structure scheme,three kinds of schemes of column axial compression ratio can meet the design requirements and meet the performance level of the requirement 1 for the deformation in the whole station structure under earthquake E2.Therefore,the three kinds of structural solutions meet the safety requirements of the design.4.For the same station,in the calculation of the relative displacement of the top and bottom,the response acceleration method the calculation results is the largest of the three method,time history analysis method is the smallest of the three methods.In the calculation of the bending moments and axial force value,the results of response displacement method are generally larger than the reaction acceleration method,the time history analysis results in smaller.For the shear value,time history analysis method shows the maximum results.