Research On The Movement And Deformation Of The Overlying Rock Mass Caused By The Excavation Of The Shallow Section Of The Futulong Tunnel

Since the shallow buried sections of mountain tunnels built in China often pass through more severely weathered sections,their rock masses are often broken and have poor stability.In addition,they are greatly affected by surface water,and they are prone to collapse and collapse during tunnel excavation.Safety accidents pose a threat to the safety of construction personnel and seriously affect the construction progress.This article takes the Futulong Tunnel as the engineering background,and combines the actual conditions of the tunnel construction in the shallow burial section.The overburden rocks of the Futulong Tunnel at different burial depths and the deformation and the different treatment measures The optimization of moving deformation was studied by numerical simulation and applied to actual engineering.The field monitoring and measurement data verified the rationality of disposal measures.The main research contents of this article are as follows:(1)Take samples from different locations on the site of the shallow buried section of the tunnel,and then perform coring,cutting,and grinding to perform indoor rock mechanics tests.The uniaxial compression tests and conventional triaxial compression tests are used to determine the physical and mechanical parameters of the rocks,thereby determining Quality evaluation of rock mass over tunnel and mechanical parameters of rock mass.(2)Use MIDAS / GTS NX to establish a three-dimensional numerical analysis model.After simulating the stress,displacement,and spatial changes of the overlying rock mass,some movement and deformation changes are obtained,and advanced pre-support is required in actual construction To ensure construction safety,further analysis is made of two treatment measures: pipe shed grouting and surface grouting in tunnel construction.The results show that both treatment measures can effectively control the movement and deformation of the overlying rock mass caused by tunnel excavation.Pipe shed grouting was selected as the site construction disposal measure.(3)Through statistical and regression analysis of the site monitoring measurements of the shallow buried section of the Futulong Tunnel,and comparison analysis with the numerical simulation results,it is proved that the excavation of the shallow buried section of the on-site tunnel is in a stable state,and the movement and deformation of the overburden rock are weakened.It basically fits the relevant results of numerical simulation.