Research On Deformation And Failure Characteristics And Evolution Law Of Overlying Rock In Stope Under Typical Deep Geological Environment

In the process of my country's energy development,with the upgrading of mining technology and the progress of production methods,the exploitation of underground engineering resources has gradually expanded to the depths.Especially in coal mining,with the depletion of surface and shallow mineral resources,underground mining shows a trend of deep extension,and deep mining is imperative.And deep coal mining will cause deformation and destruction of the overlying rock,leading to the destruction of the mechanical environment,surrounding rock characteristics and hydrogeological environment of the deep overlying rock.Therefore,studying the failure laws of mining overburden during deep mine operations is not only conducive to guiding the efficient exploitation of deep resources,but also laying a foundation for the risk assessment of deep composite coal and rock dynamic disasters.The paper summarizes the geomechanical environment of the overlying rock,the deformation and failure characteristics of the surrounding rock and the stress evolution law under the conditions of deep mining.Taking the geological conditions of the deep mining face of Zhangbei Mine as the engineering background,fuzzy comprehensive evaluation,theoretical research,MATLAB are used.Numerical analysis and FLAC3 D numerical simulation are used to systematically study the deformation and failure characteristics and evolution rules of the overlying rock in the typical deep geological environment,and the conclusions are as follows:(1)Summarize and sort out the various environmental influence factors that cause the destruction of the overlying rock in the deep stope,use the analytic hierarchy process to arrange and evaluate the different influencing factors,list the index hierarchical structure model diagram for each factor,and use the judgment matrix Single-level sorting of various influencing factors indicators,and finally a single-level sorting table to get a total sorting table of influencing factors.From the overall ranking table,the influencing factors with larger weights are obtained,and then the key influencing factors that cause the deformation and failure of the surrounding rock of the deep roadway are obtained.(2)Based on the probability integral method,and according to the actual overlying rock structure model,develop and use MATLAB numerical analysis program to develop the overlying rock deformation and failure information system of the deep stope to obtain the mechanical mechanism of the overlying rock deformation and collapse in the fully mechanized face of Zhangbei Mine.(3)Using FLAC3 D numerical simulation software,the original data model was established on the basis of the deep working face of Zhangbei Mine,and the vertical stress and horizontal stress distribution map and vertical displacement inside the model under different advancing distances of 20 m,40m,60 m,80m and 100 m were studied.Together with the horizontal displacement distribution map and the plastic zone failure evolution map,the time-dependent characteristics of the deformation and failure of the overlying rock and the failure law of the overlying rock movement under different advancement degrees during coal seam excavation are analyzed.(4)Combined with the actual engineering of Zhangbei Mine,summarize and analyze the mechanical characteristics of coal and rock mass,mining strength and support methods in the area where the working face is located,monitor the characteristics of the pressure appearance of the deep mining face,and perform quantitative analysis on it to obtain the deep work The internal law of rock movement and rock pressure during face mining.