Study On Numerical Simulation Of Geological Environment Response Of Coal Mining Subsidence Under The Influence Of Faults

In recent years,the use of numerical simulation software to simulate complex geological model is the hot spot of geological response in mining area,and it is also the guarantee of coal mine safety production and comprehensive management of mine environment.Because of the lack of geological data in the mining area,no mature theoretical system has been developed at home and abroad in response to the geologic environment caused by mining under complicated geological conditions.Therefore,it is of great significance to use numerical software to simulate the application of coal mining in complex geological conditions to the research and comprehensive management of mining environment.This paper summarizes the theoretical methods and analyzes the post-mining stress redistribution,fault activation and surface environment response under complex geological conditions in the mining subsidence area at home and abroad for the basic data of geological environment response.Taking the surface response of 11-2 coal seam mining of F02 reverse fault lower section of Xinji No.2 mine for the purpose of outdoor investigation in the study area,the geological data were collected and the numerical simulation analysis was conducted indoors.From the multi-angle,the coal mining subsidence geology Environmental response analysis and research,get the following understanding:(1)Affected by the dip angle of the fault,the stress in the mining area is redistributed and the stress concentration is located at the bottom plate of the fault.The concentration of vertical stress decreases with the increase of fault dip,but it is larger than the maximum vertical stress without fault.(2)Affected by the fault,when the working face of the lower section of the fault is gradually pushed to the fault,the vertical stress is concentrated on both ends of the working face.When the working face is advanced to the area affected by the fault,the stress is transmitted to the fault and the upper disk.The vertical stress decreases gradually.Under the condition of different inclination of fault,the vertical stress of the roof of the cut-off line is a(30°)>a(45°)>a(0°)>a(60°)>a(75°).(3)The values of tangential stress and normal stress on the fault plane are changing continuously during the progressive thrusting of the reverse fault under different dip angles.When the dominant effect of the tangential stress is greater than the tangential stress,there will be a tendency of activation slip above the fault.When the dominant effect of the tangential stress is large enough,the fault will produce shear slip.(4)Under the reverse fault conditions with different dip angles,the surface subsidence basin basically shows a symmetrical rule during the gradual advancement of the work face to the fault.The maximum subsidence value under fault conditions is greater than the surface subsidence value without faults.With the increase of fault dip angle,the subsidence under the full exploitation condition has less influence on the surface subsidence.(5)Through the analysis of surface deformation,the surface deformation and migration in the direction of the cut away from the fault are basically unaffected by the fault,and the dip of the fault near the fault changes obviously.Through the slope deformation and curvature deformation of the ground surface,it can be concluded that the surface slope on the fault plane is flatter than the fault-free one.The results of surface horizontal deformation analysis show that the peak value of surface horizontal deformation on the fault side is smaller than that on the faultless side,which also verifies this conclusion.