Analysis on the distribution characteristics of underground pressure in the fully

Due to the influence of gob shape, lateral constraint conditions of working face and other factors, the overburden movement law of the rotary fully-mechanized caving face has its own characteristics in different areas of the same working face or in different mining stages. Considering the influence of coal cutting technology and inclining mining during rotary mining on the ground pressure appearance of the stope, aiming at the roof structure and roof pressure distribution in different areas of the rotary fully-mechanized caving face, this paper takes the 301 fully-mechanized caving face of Changchunxing coal mine as the engineering background, according to its mining conditions and the rock mechanical properties of the overlying strata, based on the calculation of roof structure model in different areas of working face during rotatary mining, and uses the methods of theoretical analysis, numerical simulation and field measurement, the significant difference between the roof pressure distribution characteristics in the rotating area of the working face and the normal mining period was analyzed. The research results show that during the transfer mining period, the advance speed of the head is much faster than that of the tail, resulting in a large difference in the volume of stoping space and the mining influence range along the strike and dip of the working face in the same period. At the same time, within the influence range of triangular arc-shaped roof in the head area, with the increase of the mining transfer step distance, the farther away from the center of rotation, the larger the area of arc-shaped roof overhang. In addition, a thicker roof layer within the influence scope of overburden mining can play the role of lateral transmission force. As a result of the combined action of these three conditions, the roof pressure in the head area with a small mining space increases obviously compared with that in the area with a large mining space, which causes the stress concentration in the head area.