Abstract:
Roof failure and fracture accidents account for more than 70% of mine disasters.The main cause of roof failure and fracture is shear force.Therefore, this paper analyses the influence of the length of goaf on the stress of the coal seam internal and roof based on the theory of roof shear beam, combined with the finite element simulation results of FLAC
3D coal seam mining in a coal mine.Through the comparative analysis, it is known that there are two main factors that cause the rock burst on the roof of the coal mine.The first one is related to the length of the goaf.The larger the length of the goaf, the greater the possibility of rock burst, and the maximum value of the equivalent stress appears at one-half of length of the goaf.The second one is related to the shear stress value of the roof, the deformation system composed of the roof and the coal seam will be unstable, and there is a danger of rock burst when the value reaches the limit of the shear strength of the roof.The consistency between the finite element simulation results and the theoretical prediction results indicated that the prediction of the roof failure and fracture by the roof shear beam theory is accurate.At the same time, it has important guiding significance for predicting and preventing the roof failure and fracture of rock burst of coal mine disasters.