Study on mechanism of rock burst in fold structure area of coal mine and its prevention practice

Aiming at the problems of abnormal stress of coal and rock and frequent occurrence of strong mine tremors during mining in the fold structure area of No.402103 working face of Hujiahe mine, the stress evolution characteristics of roof, coal seam and floor during mining in the fold structure area were analyzed based on numerical simulation and field measurement, and the occurrence mechanism of rock burst in fold structure area was discussed. The simulation results show that when the working face is mined to different areas of the fold structure, the distribution of vertical and horizontal stress fields in the fold structure area has obvious zoning characteristics.When the working face is mined in the fold structure area, the horizontal stress plays a dominant role. When the working face is mined to the anticline axis area, the stability of the roof surrounding rock decreases. When the working face is mined to the syncline axis area, the stability of the floor surrounding rock decreases. The stability of the coal seam decreases when mining to the fold wing area.Based on the occurrence mechanism of rock burst in fold structure area, the prevention and control scheme of directional blasting energy release and load reduction for roof and coal seam of roadway surrounding rock system in No.402103 working face was formulated. After pressure relief, the daily average total microseismic energy decreased by 47.6%, and the daily average microseismic frequency increased by 16.7%, which effectively reduced the risk of rock burst in working face.The research results have a certain reference significance for the prevention and control of mining dynamic disasters in coal mine fold structure area.