摘要
Abstract
In response to the problem that end roof overhang during fully mechanized mining under a hard roof is prone to induce disasters such as strong mine pressure and impact air blasts,this study takes the 30203 fully mechanized working face of Hanglaiwan Coal Mine as the background to investigate its formation mechanism and explore effective active prevention and control methods.A cantilever beam mechanical model is established to analyze the nonlinear relationship among roof strength,span,and the area of the suspended roof.A method of actively weakening the roof using hydraulic fracturing technology is proposed.Through theoretical analysis,numerical simulation,and field tests,key parameters such as the inclination angle of fracturing boreholes(60°)and borehole spacing(10 m)are optimized.The results show that hydraulic fracturing can effectively promote timely roof caving,reducing the average suspended roof area from 550 m2 to less than 100 m2,suppressing roof subsidence from 426 mm to 92 mm,and decreasing the stress concentration factor from 2.63 to 2.11,thereby achieving active prevention and control of end roof overhang.关键词
综采工作面/端头悬顶/水力压裂/顶板控制/裂隙扩展Key words
fully mechanized working face/end roof overhang/hydraulic fracturing/roof control/crack propagation分类
矿业与冶金
