厚硬顶板煤层开采强矿压防治技术研究

Study on Prevention and Control Technology of Strong Mining Pressure in Coal Seam with Thick and Hard Roof

针对厚硬顶板煤层开采强矿压显现问题,以张集北矿1611A工作面为研究对象,运用固支梁破断理论对其厚硬顶板计算,得出该工作面初步垮落步距约为67.3m,顶板来压显现强烈,需对其顶板进行弱化处理。拟采取预裂爆破弱化顶板,通过相似模拟试验,对厚硬顶板预裂爆破下采场覆岩破断特征进行研究。试验表明,在预裂爆破作用下,厚硬顶板煤层开采初步垮落步距为35m,周期垮落步距15m,周期来压均匀有序。结合实际工况制定了详细的预裂爆破方案,并进行现场试验,矿压实测结果表明:厚硬顶板预裂爆破有效减小了初次垮落步距和周期垮落步距,降低了支架工作阻力,实现了现有支护设备条件下工作面的安全回采。

In view of the problem of strong mining pressure in coal seam with thick and hard roof,taking the 1611 A working face of the north of Zhangji mine as the research background,the thick and hard roof was calculated by the theory of broken solid support beam.It was obtained that the initial caving step distance of the working face was about 67.3 m,and the roof weighting behavior was strong,so the roof should be weakened.Presplitting blasting was proposed to weaken the roof.Through similar simulation test,the breaking characteristics of overburden rock under presplitting blasting of thick and hard roof were studied.The tests show that under the action of presplitting blasting,the initial caving step distance of coal seam with thick and hard roof is 35 m,the periodic caving step distance is 15 m,and the periodic pressure is uniform and orderly.Combined with the actual working conditions,a detailed presplitting blasting scheme was formulated,and the field test was carried out.The measured results of ground pressure show that the presplitting blasting of thick and hard roof effectively reduces the initial caving step distance and periodic caving step distance,reduces the working resistance of the support,and realizes the safe mining of the working face under the condition of the existing support equipment.