Study On Characteristics Of Mine-induced Stress Field In Thick Coal Seam With Rock Burst Hazard

Based on the significant impact of mine-induced stress to rock burst, this thesis has studied the characteristics of mine-induced stress field in thick coal seam with rock burst hazard, in different exploitation conditions with numerical simulation ,on the basis of the analysis of rock burst hazard evaluation which mine-induced stress play an important role in. In order to validate the result of numerical simulation, field survey of mine-induced stress has been done in domestic rock burst mine.The main contents of the thesis are as follows(1) The characteristics of coal and rock with rock burst hazard have been summarized.It is considered that coal-rock mass has burst orientation, ability of accumulating elastic energy and quick process of being destroyed.(2) The method of rock burst hazard evaluation are excessive and miscellaneous, according to the analysis of the relativity between the stress distribution laws of coal seam and rock burst hazard evaluation a conclusion is drawed that stress field and it's distribution laws play an important role in rock burst hazard evaluation.Therefor,to study the coal and rock's stress distribution laws has great significance for rock burst hazard evaluation.(3) The thesis has compared the stope's stress distribution laws and abutment pressure ahead work face between bed mining and top-coal caving with FLAC^3D.The result shows,the stress distribution laws are different,that is to say,in the condition of bed mining,the concentration degree of stress in top bed mining is obviously greater than it in bottom bed mining,but in top-coal caving the concentration degree of stress is decreased and it's incidence is wider relatively,at the same time,the magnitude of extraction-drawing ratio has certain impact to it.(4) The thesis also studied the terrane's movement laws and evolvement laws of moving block's upright and level stress with 3DEC which is proved to be congruent.It is found that,in thick coal seam,the concentration degree of stress ahead work face and in goaf's terrane are decreased by top-coal caving.(5) To compare the distribution laws of mine-induced stress between field survey and numerical simulation,the result is accordant.