| Rock burst is one of the geodynamic disasters caused by coal mining.The mechanism of rock burst is complex,and there are many influencing factors.The active fault controls rock burst.According to statistics,about 94% of 164 mines in China have large active faults around them,and the closer the mine is to the fault,the higher the frequency and intensity of rock burst.Geological disasters such as rock burst occur frequently in Hegang mining area,Heilongjiang Province,which is located in the cross influence area of Mudanjiang fault and Yilan Yitong fault.Therefore,based on the occurrence background of rock burst in the southern mining area of Hegang Coalfield,taking the active fault determined by the geodynamic zoning as the starting point,the quantitative evaluation of the complexity of the active fault within the mining area scale is of great significance to the prediction and prevention of rock burst.The paper based on the theory of geodynamic zoning,a variety of research methods such as data collection,theoretical analysis,mathematical methods and field investigation are comprehensively used.Taking the southern mining areas of Hegang Coalfield(Fuli Mine,Xing’an Mine,Junde Mine)as the engineering research background,on the basis of elaborating the mining conditions and the occurrence of rock burst in the mining area,the influence of regional geological structure characteristics on rock burst is analyzed,the active fractures in the mining area scale are divided,and the control effect of active fractures on rock burst is determined.The matter-element extension mathematical evaluation method is applied to select the influence factors such as fracture strength value,fracture density value,fracture fractal dimension value as the evaluation index of the complexity of active faults,establish the evaluation index system of the complexity of active faults,construct the matter-element extension evaluation model,and calculate the weight of the evaluation index based on the analytic hierarchy process entropy weight game coupling mathematical analysis method,The relationship between the complexity of active fault and the energy level characteristics of rock burst is established,and the positive relationship between the complexity of active fault and the risk of rock burst is determined.On this basis,considering the complexity of active fault as the natural geological factor of rock burst,starting from the conditions of natural geology,mining technology and risk relief measures,based on ArcGIS grid method,50 m is divided × With the grid unit of 50 m,using the analytic hierarchy process and fuzzy mathematics,0.25,0.5 and 0.75 are taken as the critical values of the impact risk,respectively,to predict the impact risk of the coal seams and working faces of Fuli Mine,Xing’an Mine and Junde Mine in the southern mining area of Hegang Coalfield,and determine the impact risk area.When the mining work enters into different grid units,the impact risk of the project location can be determined,and the impact prevention measures can be taken in advance.The research results of this paper are based on the control effect of active faults on rock burst in the southern mining area of Hegang Coalfield.The prediction of rock burst risk is the foothold.The complexity of active faults is taken as the influencing factor of rock burst,and the prediction index of rock burst risk is refined.Compared with the comprehensive index method,the prediction accuracy is improved,which can provide a basis for the precise prevention and control of rock burst in the southern mining area of Hegang Coalfield.There are 34 figures,14 tables and 71 references in this dissertation. |
