Application of segment pre-blasting of 52m sublevel caving of steep and thick coal seam under complex conditions

摘要

The space structure and scale of mined-out area are dynamical variable using high-sublevel fullymechanized coal caving in steep and thick coal seam. Due to segment pre-blasting, the degree of coal damage and cracks would be increased, and the complexity of the physical-geometric structure and time-space relationship of the mined-out-area would be enhanced. Firstly, the comprehensive analysis of complexity of the B1+2 workings environment and the mining technology character at Weihuliang coal mine, and the blasting parameter optimization, dynamite quantity and blasting effect were also optimized. Then, the pre-blasting was applied successfully in 52m sublevel caving and effective deteriorate coal-seam. Finally, the effect had been detected and verified by RSM-SY5-broken-zone device and YS(B)-optic-borehole-camera. It was obviously indicated that the average-forces of the front and behind support were raising based on field monitoring results. All of these could be used as referencing for the subsequent safe mining to the 102m and 18m sublevel-top-coal caving.