Study On The Stress Of Distribution In Surrounding Rock And Anti-Rockburst Design In Boundary Coal Stope

As mining intensity is increasing continually, the mining of boundary coal left after mining the conventional longwall face is a problem which is the mines have to confront in production conjoining. Theory study and actual measurement were combined to apply in this paper, the roadway layout for preventing rock burst in boundary area, the factors influencing the rock burst hazard, the movement and deformation characters of roof strata and Grand pressure law were studied.The spatial structures of overlying strata of one-sides-goaf face, two-sides-goaf face, three-sides-goaf face, four-sides-goaf face and the face which dimension small were discussed respectively, according to the complicated mining conditions. Based on elastic mechanics theory, combined with actual conditions, worked out hypothesis in reason, regarded gob hanging roof as elastic thin plates with different boundary conditions, the functions of the plates bending displacement were analyzed by kantorovich variational method.The Grand pressure law of the faces which are under the similar geological conditions but the different boundary conditions and the influence fault to the face advancing were analyzed. The schemes of roadway layout for preventing rock burst were put forward and optimized. The rock burst hazard in boundary coal mining is discussed on geologic factors and mining technology factors. The aggregative evaluation indexes of rock burst hazard state of face B1302 worked out was 0.71, so the hazard state was medium to strong.This paper took the face B1302 as the project background, through the numerical simulation, the distribution character of abutment pressure and abutment pressure in coal and strata on trend profile and lateral profile, fracture morphology of surrounding strata under different boundary conditions and different stages of mining were studied. The influence different boundary conditions to the distribution of stress in surround strata was analyzed. According to the results of numerical simulation, the face B1302 where was in rock burst hazard state divided into 5 parts, and each assessment index was worked out.Through field measurement, the roof movement law and distribution law of bearing stress in coal body was received. The ZFG5200/19/32H type sublevel caving hydraulic support can satisfy the requirement of mining boundary coal faces. The measures for preventing rock burst were prove a successful way.