深孔预裂爆破强制放顶技术的研究与应用

摘要

For the hard and thick roof or Guqiao mine may happen large overhang , and the suspension of roof has the possibility of gas storm and a strong impact after the fracture , so in the 1123 (1) working face of Guqiao coal mine, the deep hole pre-splitting blasting weakening hard roof technology was studied .The experiment result showed that after weakening the hard roof in 1123 (1) working face of guqiao coal mine by the deep hole pre-split-ting blasting , the first caving step distance of the roof decreased from the prediction value of 45-50 m to 27.3 m or so, the bealing pressure of the pillars were in the acceptable range , and the situation of overwhelming support by strong pressure of roof did not appeared .The gas concentration in the air return way was controlled under 0.6%, and the gas drainage quantity was stable in 70m3/min, and the gas overrun and coal and gas outburst did not occurred .%针对顾桥矿坚厚硬顶板会出现大面积悬顶的情况，且大面积悬露的顶板突然断裂后有压倒支架、产生强冲击瓦斯风暴的可能性，故在顾桥矿1123（1）工作面实施深孔预裂爆破弱化坚硬顶板技术的研究。通过试验表明：顾桥矿1123（1）工作面在实施深孔预裂爆破弱化坚硬顶板后，顶板的初次垮落步距从预测的45-50m减小到27.3m左右，支柱承受压力在可以接受范围内，未出现顶板强烈来压压倒支架的情况；回风巷中瓦斯浓度控制在0.6％以下，抽采瓦斯量稳定在70 m3/min，未出现瓦斯超限和煤与瓦斯突出的情况。