小保当矿2^(-2)煤大采高综采面支架工作阻力确定

Shield working resistance in fully mechanized longwall face with large mining height of Xiao Bao Dang 2^(-2) coal seam

小保当矿2-2煤层部分区域拟采用7.5 m大采高综采面,在我国尚属首例。通过相似材料模拟实验,对工作面开采进行了研究,结果表明:覆岩中坚硬岩层形成的"悬臂梁"与"砌体梁"动态结构交替出现,造成顶板大小周期来压现象,工作面来压频繁剧烈,平均周期来压步距为17.72 m,支承压力峰值出现在距煤壁12~24 m位置处,煤壁压剪破坏区范围增大、破坏程度加剧,易片帮,覆岩运动最终波及至地表。综合计算分析和实验结论得出,支架选用5.15 m×2.05m,工作阻力22 000 k N(压强为2.08 MPa)的两柱掩护式支架进行支护,可以满足安全生产要求。研究结果对小保当煤矿开采具有指导作用,对相似矿井具有借鉴意义。

It is the first practical case that we plan to adopt fully mechanized longwall face with a mining height of 7. 5 meters for some regions of Xiaobaodang 2- 2coal seam in China. We take the similar simulation experiment and study on working face mining,the results showed that ＂cantilever beam ＂and＂voussoir beam＂dynamic structure in the hard rock of overlying strata appeared alternately,which caused the varying degrees of periodic roof pressure phenomenon and the behavior is frequent and dramatic in working face,the roof periodic weighting interval is 17. 72 m,the peak of abutment pressure locates at the ahead of coal wall with 12 ~ 24 m,the range of compression and shear failure zone and the degree of destruction are increasing,meanwhile,the breakage of coal wall is widespread and rib spalling,it can finally cause the overlying strata motion swept to ground surface. According to a comprehensive calculation analysis and experimental conclusions,we can obtain that the 2- leg shield support which is the structure of 5. 15 × 2. 05 m with the working resistance of 22 000 k N（ intensity of pressure is 2. 08MPa） can satisfy the requirements of mine safty production. Moreover,it plays a guiding role in mine extracting for Xiaobaodang coal mine,and provides reference for similar coal mines.