| With the improvement of economic and technology,Zhejiang area are vigorously construction of traffic industry,simultaneously promote the construction of the tunnel.The research of this topic is shallow-buried bias tunnel in weak surrounding rock in Zhejiang,the surrounding rock of the tunnel is mostly in weak and broken state,there are many shallow buried bias sections in the multi-arch tunnel,poor surrounding rock conditions.These tunnels have been the focus of research,there are still some problems that need to be discussed and solved by researchers.Based on the Yayu tunnel as the supporting project,mainly from the construction excavation method,Midas GTS NX and deformation law and monitoring measurement.The research content is as follows:(1)On the basis of soft rock and shallow buried bias tunnel,through the definition of soft rock properties and related mechanical properties analysis,find out the formation of shallow buried biased tunnel,and details concerning Calculation method of surrounding rock pressure.(2)The common construction methods of multi-arch tunnel are analyzed,the simulation analysis of the construction stage of the multi-arch tunnels by Midas GTS NX,the numerical results are compared and analyzed,by comparing the calculation results of different excavation sequences,concluded in shallow buried side is better excavated first.(3)The parameters of the key support measures of the tunnel were analyzed by numerical simulation,and the suggested values of the key support parameters of Yayu tunnel were given.For the background engineering analyzed,the optimal insertion elevation angle of the left hole with large bias load in Yayu tunnel is 4,and the insertion elevation angle of the left hole with small bias load is 3,the optimal diameter of the left hole of the pipe shed is 159 mm,the optimal diameter of the right hole is 108 mm.(4)The relationship between the subsidence convergent deformation of the surface subsidence vault and the excavation process is studied.The monitoring data of Yanyu tunnel are sorted out,and the field data are used to verify the scientific of the numerical simulation. |
