厚煤层综放回采率对坚硬顶板破断步距影响机制

Mechanism of Mining Rate Influencing Hard Roof Breaking Step in Fully-mechanized Caving Face in Thick Coal Seam

针对新疆潘津煤矿2301厚煤层综放工作面回采率影响坚硬顶板破断步距问题,利用现场实测和理论分析方法,通过分析顶煤作用下坚硬顶板结构形态,研究了综放开采回采率对坚硬顶板破断步距影响机制。结果表明:坚硬顶板厚煤层综放期间,顶煤对上覆基本顶关键层产生挤压作用,厚煤层回采率增大时基本顶关键层所受下方支撑力将明显减小,使工作面呈现顶板破断步距减小的特征;厚煤层厚度与坚硬顶板厚度之比n越大、强度之比m越小时,厚煤层回采率对坚硬顶板破断步距影响越明显。

Aiming at the problem of mining rate influencing the hard roof breaking step of fully-mechanized caving face in the2301 thick coal seam in Xinjiang Panjin Coal Mine,based on the field observations and theoretical analysis,we studied the mechanism of mining rate influencing hard roof breaking step through analyzing the structure of hard roof that supported by the top-coal.The results show that the top coal compresses the key layer of overlying basic roof during the fully mechanized caving of hard roof thick coal seam,and when the recovery rate of thick coal seam increases,the supporting force under the key layer of the basic roof will decrease obviously,which makes the working face show the feature of decreasing the break step of roof.When the ratio n of thick coal seam thickness to hard roof thickness is greater and the ratio m of strength is smaller,the influence of the recovery rate of thick coal seam on the fracture step of hard roof is more obvious.