极近距离煤层变厚度顶板下部回采巷道综合控制技术

针对三交河矿极近距离煤层采空区下变厚度顶板下部煤巷布置及合理支护的技术难题,通过上部残留煤柱应力扩散分析与提高掘采回收效率考量,确定601首采面两巷采用反向大错距的布置方案。在开展现场巷道顶板窥视、锚固力测试与预紧扭矩转化试验的基础上,提出了适应不同地质条件的煤巷差异化支护方案:架棚-锚杆联合支护、锚杆-锚索支护及锚杆-钢带-锚索支护。在井下实施了两条回采巷道的全进尺支护示范,监测结果表明:掘巷期间锚杆锚索工作载荷快速稳定,预紧力设计合理,围岩最大变形量30mm;回采期间超前巷道顶板最大下沉93mm。相关回采巷道综合控制技术保障了近距离下部煤层的安全高效开采。

Combined Control Technology of Mining Roadway under Variable Thickness Roof of Ultra-close Seams

Aiming at technical problem of lower coal roadway arrangement and the appropriate support with variable thickness roof under ultra-close seams goaf in Sanjiaohe colliery, through stress distribution analysis of the upper residual coal pillar and consideration of improving mining recovery efficiency, the two roadways of 601 mining workface are located with the layout scheme of reverse long distance. Based on the on-site roadway roof peeping, anchorage force test and setting torque transformation test, different support programs are proposed for adapting different geological conditions in coal roadway: combined support with steel shed and anchor bolt, anchor bolt - cable support and anchor bolt - steel strip- cable support. In the implementation demonstration of two undermine roadways support with full excavating footage, monitoring results show that: anchor bolts working-load turned stable fast, the pretension designed rationally, with the maximum amount of surrounding rock deformation of 30mm during driving period; and during mining period, prohead roadway section deformed with the maximum amount of roof subsidence of 93mm. The related coal roadway integrated control technology guarantees the safe and efficient mining on the lower portion of the close coal seams.