Study On Mining Stress Evolution Law And Surrounding Rock Control Technology Of Complex Working Face In Deep Mine

In view of the problems of stability control of surrounding rock in working face,stability control of surrounding rock in mining affected area of mining roadway and difficulty in prevention and control of rock burst in the mining process of working face under complex geological conditions of kilometer-deep mine,taking Zhangshuanglou Coal Mine of Jiangsu Xukuang Energy Co.,Ltd.as an example,the evolution law of mining stress in abnormal areas such as bifurcation merging area,fault development area and folding area of kilometer-deep well is deeply studied.The failure law of mining surrounding rock in irregular mining roadway with large coal thickness and dip angle is analyzed,and the corresponding surrounding rock control technology is put forward.The research results provide a theoretical basis and reference for the prevention and control of mine pressure disasters in the area affected by advanced mining of working face and mining roadway under similar geological conditions in the deep.The main research achievements of this dissertation are as follows:(1)Theoretical analysis,similar simulation and numerical simulation have obtained the stress distribution of the original rock and the evolution law of mining stress in the coal seam bifurcation and merging structure area.Influenced by the changes of geological weak surface and coal thickness,the advance direction of the working face from the bifurcation area to the merging area shows a change law that the peak value of the advance abutment pressure first decreases,then slowly rises and finally becomes stable,while the advance direction from the merging area to the bifurcation area shows an evolution law that the advance direction first slowly decreases and then gradually increases to stable.In addition to the sharp corner area of bifurcation merging,the other areas are the stress peak increase area,which is the key prevention and control area of high stress in the bifurcation merging area.(2)The mechanical model of fault plane is established,the mechanical mechanism of fault activation under the influence of mining is analyzed,and the criterion of positive and reverse fault activation and the relationship between the minimum critical value of fault activation and fault dip angle are obtained.The evolution characteristics of mining stress and the range of peak elevation area under the influence of fault are obtained by physical and numerical simulation.The influence of different fault inclination,number of faults,advancing direction and mining parameters on the evolution of mining stress is studied by numerical simulation.(3)The evolution law of mining stress in the dip anomaly area of deep working face with developed fold is simulated by numerical simulation method.The results show that the ridge point and its vicinity are the most concentrated areas,followed by the inflection point and the trough point and its vicinity.The correctness of the numerical simulation results is verified by the analysis of the mining pressure monitoring data.(4)The deformation and failure characteristics and mechanism of surrounding rock in the mining affected area of right-angled trapezoid roadway in the abnormal dip angle and thickness of coal seam are analyzed theoretically,and the influence of abnormal coal thickness dip angle area on roadway deformation and failure is obtained.Numerical simulation and experimental research method are used to study the deformation and failure of right-angle trapezoid and the influence law of area with abnormal coal thickness and dip.Combined with theoretical analysis and numerical simulation,the key deformation and failure areas of right-angle trapezoid roadway are summarized.The combined support-weak part reinforced-strong part unloaded support technology is proposed for key prevention and control areas.(5)With the help of the comprehensive monitoring and early warning system of rock burst in Zhangshuanglou Coal Mine with multi-parameter comprehensive early warning cloud platform,dual-source integrated stress field CT detection system,microseismic monitoring and early warning system and ground sound monitoring system as the core,the correctness of the theoretical and simulation research conclusions is verified.According to the above research,the high stress concentration area in the abnormal area of coal thickness,fault area and abnormal area of coal seam dip angle in deep working face determines the key prevention and control range of mine pressure disaster,and puts forward the corresponding pressure relief technique,which effectively controls the occurrence of mine pressure disaster accidents.This dissertation has 115 figures,7 tables and 164 references.