Study On Construction Dynamic Response And Control Technology Of Large Cross Transfer Station In Rail Transport

Underground rail transit is generally shallow buried tunnel,and there are a variety of building,municipal pipe network,etc around it,and because the rail transit transfer hub and the relationship between the rail transit interval are complex and influence each other,so it it is quite difficult to design and construction.At present,the construction of the underground rail transit is still in its infancy,and the technology of it is not mature relative to the ground traffic,Especially the Large underground interchange station,and it has a number of construction problems,such as it has a large space span,the hub influenced each other,and so on.Therefore,the construction technology of the rail transit transfer hub is the forefront of research problems in underground engineering.In view of this,in this paper,based on the science and technology project of Chongqing(No.CSTC2010AC6105),it has used the theory analysis,and engineering analogy,and numerical simulation,and field monitoring measurement techniques in combination,the mechanical response and control technology of the shallow buried large underground cross transfer station have been researched systematic.The major research content is as follows:(1)Structure optimization analysis and excavation method research on the large cross transfer station of rail transitRelying on Hongqihegou station of chongqing rail transit project,the internal arrangement type and the structure design of the station is analysed,and the "arch-wall" intersection of the large section is put forward.On this basis,dynamic construction process of the large cross interchange station under the different excavation method is simulated by the numerical simulation method,the displacement of the tunnel and the surrounding rock is analysed,and the force of the structure is co MPared under the different excavation method.The results show that the divided heading constructing method is more suitable for fast excavation of the large cross section bored tunnel.(2)Study on the construction mechanical response of the large cross transfer station of rail transitAccording to the stability evaluation of surrounding rock for underground engineering,the calculation formula of yield proximity of surrounding rock based on Mohr-Coulomb criterion is deduced,and the stability evaluation method of surrounding rock based on Yield proximity of surrounding rock is introduced,which provided theoretical basis for estimating the stress state and yield of the surrounding rock accurately in the process of dynamic construction.On the basis,first of all,the 3D finite element calculation model of the single large section is established,and the dynamic response rules of shallow buried station during construction is analysed.Second,the 3D finite element calculation model of the large cross transfer station is established,and research of the construction mechanical response and stability of surrounding rock is carried out,the mechanical characteristics of the surrounding rock in cross position is analyzed.The calculation results show that the steps of construction sequence and the supporting measures for the station of line 3 and line 6 is meeting the requirements,and the tunnel is safe.(3)Study on the influence and control technology of the construction of large cross transfer station of rail transitIn view of the settlement control standards of the large underground station,the different standards of surface subsidence which controlled by the surface buildings ro the environment requires are analyzed,and the the limits of the earth's surface subsidence on Hongqihegou station in chongqing rail transit is calculated according to the different standards,such as Peck formula,ultimate tensile strain,and ultimate strain of the strata.The three-stage evaluation method which include Greenfield model of the housing broken,isolation method,and integral analysis method are put forward through the analysis of the evaluation criteria of damaged buildings.Then,the blasting control standard of the Hongqihegou station is researched,and the blasting control technique is proposed.(4)Study on the structural design scheme and construction methods of large cross transfer station of rail transitBased on the conventional structural design scheme and construction method in underground railway stations,the strengths and weaknesses of the double wall pilot tunnel method have been analyzed,the construction methods of the divided heading constructing and wall before the arch method are put forward,which method is carried out on Hongqihegou station of chongqing rail transit project.On the basis of this,the overall implementation steps of the station and the construction scheme of the structure mutation are put forward.(5)Study on information construction technology of large cross transfer station of rail transitBased on the basic requirement of the underground engineering construction monitoring,dynamic monitoring and feedback system of the rail transit underground tunnel is developed,and it can be easily to analysis and process tunnel monitoring data through this system.Based on this,through the monitoring measurement for Hongqihegou station,the mechanical parameters and deformation characteristics of surrounding rock are analyzed in the process of the construction by used of reverse analysis method of monitoring data and numerical calculation method,it can put forward suggestions for the optimization measures of the design and calculation parameters and excavation method of the tunnel.So then the informationization construction method is realized.The main innovation point is as follows:(1)The "arch-wall" intersection of the large section is put forward for the large cross transfer station of rail transit,the key technologies of structure design for the large cross transfer station of rail transit is acquired.(2)Rely on construction mechanics analysis and model test research for the large cross transfer station of rail transit,the construction mechanics response law is comparatively studied for two methods of Double wall pilot tunnel method and Up and down side heading method,and on this basis scope of application is put forward for two methods in super large section excavation.(3)The construction method which set aside part of the core soil,inverted arch after doing double wall pilot tunnel method,and top and bottom side gate + arch after wall first set aside part of the core are firstly put forward for the large cross transfer station of rail transit.