Long Distance Shallow Buried Tunnel Surrounding Rock Stability Analysis And Engineering Application

With the rapid growth of China's economy,a large number of tunnels and underground engineering have been constructed,such as railway,highway,water and electricity,national defense,city metro and so on.Especially the urban rail construction have made a fairly large shallow buried tunnel.As a result,it is particularly important for us to research shallow buried tunnel research.This paper mainly through the field test and numerical simulation,combining the project of PanLong tunnel,researching the shallow buried the stability of surrounding rock,and supporting optimization,the main research contents is as follows:(1)This paper summarize the surrounding rock stability research status at home and abroad,especially the research status of shallow-buried highway tunnel,learning theory of surrounding rock stability analysis,summarizes the factors of affecting the stability of surrounding rock,and the three-dimensional fast Lagrangian were introduced.(2)Through system collects and sums up the tunnel instability hundreds cases of typical geological radar data,and the reference literature,selected level of surrounding rock,rock mass integrity condition,excavation span,tunnel buried depth of ground water,bias Angle,and construction management and technical level seven main factors as the risk of tunnel surrounding rock stability evaluation index and risk evaluation model of tunnel surrounding rock is established.(3)According to the actual project size,and combining with the size of saint venant principle to deside the size of model,and using ANSYS to establish model partitioning grids.Finally,simulating the construction excavation supporting process,in the FALC,and analysing the deformation law of surrounding rock of long distance shallow buried tunnel.(4)Monitoring the deformation and stress of surrounding rock during construction,Collecting the monitoring data of the shallow buried section continuous,Combining with numerical simulation of the deformation law of surrounding rock to control the deformation of surrounding rock and put forward support optimization design,and modify the numerical calculation of supporting parameters in the model,to verificat the deformation of surrounding rock to optimize the results.