Analysis Of Time-effect Deformation Mechanism And Stability Of Surrounding Rock Of TBM Tunneling In Coal Mine

Full-face tunnel boring machine(TBM)has been widely used in engineering fields such as transportation,water conservancy and urban rail transit because of its advantages of mechanization,high degree of automation,fast excavation speed,and good safety.However,due to deep burial,large ground stress,complex geological conditions,narrow transportation space,and poor operating environment,underground coal mine tunnels are still in their infancy.The deformation and damage mechanism of surrounding rocks and safe and efficient support technology are urgently needed.Research.To this end,this article takes the TBM excavation project of 1712A high-extraction roadway in Zhangji coal mine in Huainan mining area as the background,and adopts the method of indoor test,theoretical research,numerical analysis and field measurement to aim at the time-dependent deformation mechanism and stability of the surrounding rock of TBM excavation roadway in coal mine.The main contents of the analysis and research are as follows.Through sampling and in-situ stress test of-677m working face underground in Zhangji Coal Mine,the in-situ stress value is obtained.The sandy mudstone is subjected to a uniaxial compression test to obtain its peak strength and elastic modulus.Based on the sandy mudstone uniaxial creep test curve,the non-linear least square method is used to fit the uniaxial creep test results to obtain the relevant parameters of the CVISC creep model.The elastic solution of the surrounding rock of a circular roadway and the displacement solution of the CVISC creep model under the action of non-uniform load are deduced;based on the constitutive equation of the CVISC creep model,the analytical solution of the displacement of the surrounding rock of the roadway and the support reaction of the roadway support structure are solved.force.Taking the 1712A high-drawing roadway of coal mine TBM as the engineering background,the FLAC-3D finite difference method numerical simulation software is used to construct a three-dimensional numerical analysis model.Based on the FLAC-3D CVISC creep model,the rock creep model parameters obtained from the test are introduced.A 100-day simulation of the creep deformation of the surrounding rock of the roadway under different support conditions was carried out to obtain the time-dependent deformation characteristics of the roadway surrounding rock and the stress field,displacement field and plastic distribution area of the roadway under various support conditions.Based on the above-mentioned research results,the optimization plan of 1712A high-drainage roadway support is proposed based on the evolution law.Carry out on-site monitoring of TBM tunnels in coal mines,and obtain the deformation,separation,and bolt force characteristics of the TBM tunnels.The test results show that the maximum axial force of the bolts after TBM tunneling is 79.53KN,and the maximum deformation of the tunnel surrounding rock is 12.24mm,the maximum separation of the roof is 11.5mm,which is more consistent with the numerical simulation results.The optimized support scheme adopted can effectively control the deformation of the surrounding rock and the roadway stability is good,stability control and support design provide reference.Figure[55]Table[18]Reference[161]...