Model Test Study On Deformation Characteristics Of Surrounding Rock In Urumqi Subway Tunnel

Under the background of large-scale development of urban rail transit,the underground traffic mode has been more used in the construction of western cities.In the shallow buried excavation project,the surrounding rock deformation is a very important safety reference factor.Through the displacement value and stress variation of the surrounding rock deformation,the deformation of the surrounding rock caused by tunnel excavation can be understood.In this paper,a similar simulation test and numerical simulation method are used to analyze the influence of surrounding rock deformation and stress change on tunnel excavation by using the example of upper and lower step construction method in Sanlubei Station-Xinjiang University section tunnel of Urumqi Metro Line 1.The research work is as follows:(1)Taking the Sanyabei Station-Xinjiang University Station of Urumqi Metro Line 1 as the engineering background,the model test similarity ratio is determined by the similarity theorem and the actual situation,and the model material and model size are determined by the ratio test.The monitoring scheme of the stress sensor and the FARO 3D laser scanner was designed to monitor the stress and deformation of the surrounding rock of the tunnel,and the tunnel excavation was carried out according to the excavation sequence of the upper and lower steps.(2)Through the monitoring of the tunnel excavation of the up-and-down step method in the model test,the progressive failure process of the surrounding rock of the tunnel is described,and the convergence characteristics and stress changes of the surrounding rock of the tunnel and the settlement characteristics of the vault and the characteristics of the surface settlement are described.Analyze.(3)Based on the geological and tunnel structural parameters used in the above similar material simulation test,the numerical simulation method is used to simulate the tunnel construction,and the convergence value and stress variation of the tunnel and the settlement value of the dome and the surface are obtained.The settlement value and plastic zone change,which verifies the accuracy of similar material simulation test results and the rationality of similar material simulation test application.