中厚煤层小煤柱沿空掘巷“卸压-加固”围岩控制成套技术研究

    Research on complete set of technology for “pressure relief-reinforcement” surrounding rock control in gob-side entry driving with small coal pillars in medium-thick coal seams

    • 摘要: 为了解决中厚煤层沿空掘巷支承应力大、变形严重等问题,提出了以“超前切顶卸压+对拉锚索注浆加固+巷内辅助支护”为主体的中厚煤层小煤柱沿空掘巷“卸压-加固”围岩控制成套技术,并以乌兰木伦煤矿中厚煤层工作面为技术背景,利用理论计算和数值模拟,分析了中厚煤层小煤柱沿空掘巷“卸压-加固”围岩控制关键参数。研究结果表明:煤柱及巷旁支护体支撑阻力为2 891.2 kN,当煤柱宽度为4 m,小煤柱内布置3根对拉锚索时,小煤柱的支撑强度满足要求;当采用Φ194 mm×8 mm的钢管配合C40等级的混凝土进行巷内辅助支护时,沿空掘巷能够满足长期使用要求。“卸压-加固”沿空掘巷煤柱塑性程度明显降低,煤柱和巷道变形量显著减少,煤体侧支承应力影响深度仅2.12 m。现场应用表明,中厚煤层小煤柱沿空掘巷“卸压-加固”围岩控制技术能够有效控制沿空掘巷围岩变形量,应用效果显著。

       

      Abstract: In order to solve the problems of large bearing stresses and deformation along the gob-side entry driving roadway of medium-thick coal seam, a complete set of “pressure relief reinforcement” surrounding rock control technology for small coal pillars driving along goaf in medium thick coal seams is proposed, with the main body being “advanced roof cutting pressure relief, opposite anchor cable grouting reinforcement, and auxiliary support in the roadway”. Taking Wulanmulun Coal Mine as the technical background, the key parameters of the gob-side entry driving in the medium-thick coal seam are analyzed by using theoretical analysis and numerical simulation. The results show that the support resistance of the coal pillar and roadside support body is 2 891.2 kN. When the width of the coal pillar is 4 m and 3 pairs of anchor cables are arranged in the small coal pillar, the supporting strength of the small coal pillar meets the requirements. When the steel pipe with Φ194 mm×8 mm in the thickness is used with the C40 grade concrete for auxiliary support in the roadway, the gob-side entry driving roadway can meet the requirements of long-term use. The newly “pressure relief-reinforcement” surrounding rock control technology could strongly decrease the deformations of coal pillar and gob-side entry driving and minimize the plastic degree of the coal pillar. By monitoring the displacement of the surrounding rock in the gob, the “pressure relief-reinforcement” surrounding rock control technology of the gob-side entry driving with medium-thick coal seams and small coal pillars can effectively control the surrounding rock deformation of the gob, and the application effect is remarkable.

       

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