Abstract:In order to explore the characteristics of local coal rib spalling in large mining height working face and put forward effective measures to control the stability of coal wall, the characteristics of coal rib spalling in the advancing process of large mining height working face were studied through the statistics of the shape of coal rib spalling in working face and 3DEC numerical simulation, and the measures to control the stability of coal wall in large mining height working face were put forward. The results show that the main forms of coal wall spalling in large mining height face are the overall failure of coal wall induced by coal shear slip, shear slip failure, tensile fracture failure, fracturing failure and plate crack failure, and the frequency of each spalling form is smaller in turn. Under the influence of mining, the larger horizontal displacement distribution and spalling range of coal wall are mainly in the middle and upper part of the working face, accounting for about 3/4 of the mining height, spreading from the upper part to the middle and lower part, and finally running through the whole coal wall and extending to the depth of the coal wall. Finally, the spalling of coal wall with large mining height presents the characteristics of large degree, wide range and large depth. In addition, 12 main influencing factors of coal rib spalling in large mining height face are summarized and analyzed, and the control measures of coal wall stability in large mining height face are put forward from the perspective of direct controllable factors and indirect controllable factors respectively.
