The Construction Technology Of The Shallow Large-cross Rail Transit Tunnel In Backfill Of The Mountain City

Rational developing and utilizing the underground space is a very effective solution way to solve the problem between the urban development and the insufficient land resources for promoting sustainable urban development. Therefore, the construction of urban rail transit is increasingly subject to national attention. It is inevitable in to building a large number of large span tunnel in the complex environment because of environmental constraints.It is inevitable that the rock and soil will be disturted due to the deformation of tunnel surrounding rock and soil. The significant features of the urban tunnel project are shallow, poor geological conditions, dense surface buildings and underground pipelines. These features of the city tunnel project tunnel construction may generate large deformation and passed on to the surface. These will affect the the safety of the buildings on and the use of the pipelines which caused by a series of geotechnical environmental issues.The people’s awareness of environmental protection have constantly enhenced today, so It has great significance to researching the construction technology Of the shallow large-cross rail transit tunnel.We researched the most complex interval period backfill section tunnel which from SK11+872to SK11+917.5of the third line of the chongqing rail transit in the paper. This interval period from huaxin stree to guanyinqiao.And the thesis mainly research work and achievements are as follows:One:This project attempts to ues the WSS grouting construction technology in the backfill formation, the process is an effective means to improve the mechanical properties of the backfill soil,The soil physical and mechanical indexes of the formation is greatly improved through the pre-reinforcement.Two:According to the specific circumstances of the tunnel construction, we use the numerical simulation software to calculate the dynamic construction process.Three:We comprehensively discussed the CRD method in the tunel construction.The method is a mining method which embodied the design philosophy from small to large and from small to large.Four:The paper studied the control indicators included environment,tunnels force and deformation, and the advanced monitoring measurements have been builtThe surface subsidence, supporting deformed, and structural stability of the different stages of excavation were analyzed and discussed through monitoring and measuring instruments,and then determine the structural stability and safety.