Simultaneous Construction Control Technology Of A Transfor Metro Station

With the increase of urban subway lines,the number of transfer stations is also increasing,but the new transfer subway stations often need to pass through the existing stations,which will affect the stability of the original station structure.Therefore,the number of transfer subway stations built once is gradually increasing.Before the construction of the new subway line,the location of the transfer station is planned in advance,which reduces the damage of the new station to the original station and ensures the normal operation of the existing line.This thesis takes the transfer station Xiayuan Station of Taiyuan Metro Line 1and Line 3 as the engineering background.Xiayuan station adopts the construction scheme of one-time completion.According to the work plan,the main body of line 1and the transfer node station are excavated first.After the main body of line 1 is completed,the upper road is restored and the main body of line 3 is constructed.The main research contents and conclusions are as follows :(1)The analytic hierarchy process(AHP)is used to compare the construction methods of Xiayuan station.The evaluation indexes are selected from four aspects :environment,economy,safety and technology.The evaluation system is established.The construction methods of transfer node cover excavation,cover excavation semi-reverse method and cover excavation reverse method are compared.(2)The top-down construction technology of transfer node in Xiayuan station is summarized,and the construction technology of concrete filled steel tube column,foundation under column and steel reinforced concrete beam is mainly summarized.(3)Abaqus is used to simulate the top-down method of transfer node.Two models are established for the top plate of transfer node and the negative layer of underground plate with or without steel,and the calculation results of the two models under the same working conditions are compared.It is found that the top plate steel can effectively reduce the deflection of the top plate after covering the soil,but it has little effect on the retaining structure and the surrounding surface.From the cost and construction difficulty,the design of the steel beam of the underground negative plate can be reasonably optimized.(4)The numerical calculation of the whole construction process of the Xiayuan station is carried out.Due to the symmetry of the overall design and construction scheme of the Xiayuan station,the Xiayuan station is reasonably simplified,and a quarter model of the Xiayuan station is established to simulate the whole process of the first construction of the Xiayuan station.It is concluded that each layer of the cover-excavation reverse method plays a supporting role.During the construction of the transfer node,the surrounding surface settlement,the deformation of the diaphragm wall and the supporting axial force are smaller than other standard sections.(5)The field measured data such as the deformation of the retaining structure,the vertical displacement of the surface and the axial force of the inner support during the excavation of the Xiayuan station are analyzed and compared with the calculation results of the finite element model established in this thesis.The field measured data and the numerical simulation results are in good agreement,which verifies the rationality and reliability of the numerical simulation and provides a reference for similar projects.