软弱厚煤层“三沿”布置技术应用研究

Application Research on"Three Along"Layout Technology in Weak-Thick Coal Seam

软弱厚煤层工作面掘进回采巷道,通常采用沿底掘进,存在冒顶风险,且不易推广无煤柱开采。针对煤层厚度变化和煤层软弱的特点,提出一种“三沿”技术,即利用煤层顶板较为坚硬的特点,采用主动锚网索支护的方式进行回采巷道的“沿顶掘进”,使用定向预裂爆破技术实现切顶卸压“沿空留巷”,以及采用“主动锚网索+木垛+U型钢支架”的支护方式进行超前卧底形成超高巷道来实现煤炭最大程度的“沿底回采”。根据工作面开采动压影响和切顶卸压原理,在距离工作面不同距离范围内分别设计了6个阶段的动态支护参数。工程实践表明,沿顶掘进有利于巷道稳定和沿空留巷技术的应用,同时能够最大程度地回收煤炭资源。该技术解决了软弱厚煤层沿底掘进巷道支护困难、留设煤柱浪费资源等问题。

For the mining roadway in the weak-thick coal seamworkingface,the roadway is usually driven along the bottom,which not only has the risk of roof fall,but also is not easy to promote pillar free mining.According to the variation of coal seam thickness and the characteristics of coal seam weakness,a"three along"layout technology is proposed.The key technology is to make use of the characteristics of the hard roof of the coal seam,adopt the active bolt mesh cable support to drive along the top of the mining roadway,use the directional prespliting blasting technology to realize the roof cutting and pressure relief,and retain the roadway along the goaf,and adopt the support mode of"active bolt mesh cable+wood pile+U-shaped steel support"to form an ultra-high roadway to realize the maximum bottom mining of the working face.According to the influence of mining dynamic pressure and the principle of roof cutting and pressure relief,six stages of dynamic support parameters are designed in different distances from the working face.Engineering practice shows that heading along the top is conducive to the stability of roadway and the application of roadway retention technology along the goaf,and can recover coal resources to the greatest extent.This technology solves the problems of difficult roadway support along the bottom ofweak-thick coal seam and waste of resources by leaving coal pillars.