To ensure the mining safety of working face in the protective seam and meanwhile extract pressure-relief gas of the lower protected seam and eliminate its outburst risk,the present study researched into fracture devel...To ensure the mining safety of working face in the protective seam and meanwhile extract pressure-relief gas of the lower protected seam and eliminate its outburst risk,the present study researched into fracture development of floor coal-rock mass of the protective seam and migration rule of pressure-relief gas from a protected seam so as to obtain an effective pressure- relief gas extraction method.The results show that after the upper protective seam was mined,mining-induced fracturing floor coal-rock mas...展开更多
基金Funded by the Major State Basic Research Development Program of China(No.2005CB221503)the Key Program of the Natural Science Foundation of China(No.70533050,50904068 and 50674089)
文摘To ensure the mining safety of working face in the protective seam and meanwhile extract pressure-relief gas of the lower protected seam and eliminate its outburst risk,the present study researched into fracture development of floor coal-rock mass of the protective seam and migration rule of pressure-relief gas from a protected seam so as to obtain an effective pressure- relief gas extraction method.The results show that after the upper protective seam was mined,mining-induced fracturing floor coal-rock mas...
