厚煤层沿顶掘进巷道袋式充填顶板支护技术研究

Study on top bag filling roof supporting technique in thick coal seam roadways developing along roof

为解决工作面沿底回采造成工作面端头底部三角煤大量损失的问题,提高煤炭资源采出率,在厚煤层沿顶掘进回采巷道实施超前开挖回采底煤工作。在实施超前开挖回采底煤工作时形成了超高回采巷道,因此需要减少超高回采巷道变形。矿井原采用木垛充填降低回采巷道高度以此维持超高巷道稳定,但木垛充填存在工作量大、工人劳动强度大、效率低、接顶不充分、承载能力低且易变形、单体支柱工作阻力小、受力不均、稳定性很差、易发生倾倒等问题,对工作面的安全回采构成严重威胁,基于以上原因,结合贺驼矿现场开采技术条件,提出了采用双液注浆充填材料进行袋式充填顶板支护的开采技术。该技术的实现方式为在工作面超前支承压力影响范围内巷道中超前挖底,挖底后在巷道中部搭建充填体支撑平台,平台采用单体支柱支撑,平台上放置充填袋,充填袋顶面悬挂在巷道顶板上,充填袋自由面侧加装挡杆、金属网、木板(防止充填袋胀破),往充填袋内充入空气使之膨胀至完全贴合充填空间,之后用高速制浆机往里充填浆液。经过现场工业性试验,结果表明超高回采巷道采用新型注浆充填材料实施顶部充填技术,单体支柱支护强度12.3-25.7 MPa,效率高,有效改善了区段巷道顶部的整体性和稳定性。

In order to solve the problem of a large amount of loss in the bottom of the working face caused by mining along the bottom of the working face,and to improve the recovery rate of coal resources,the mining roadway along the top of thick coal seam is carried out to mine the bottom coal in advance.It is necessary to reduce the influence of the ultra-high mining roadway on the normal mining of the working face because of the formation of the ultra-high mining roadway in the advance excavation of the bottom coal mining.The mine originally used wood cribs to reduce the height of the retracted roadway to keep the ultra-high mining roadways stable,but the wood fill support la⁃bor intensity was large,the efficiency was low,the top contact was insufficient,the carrying capacity was low and easy to deform,the working resistance of the single support was small,the force was uneven,the stability was poor,and itwas prone to fall,which posed a se⁃rious threat on the safety retreating of the working surface.Based on the above reasons,combined with field mining technical condition of Hetuo coal mine,the mining techniques for carrying the top bag filling using a double liquid grouting material was proposed to use.The implementation of this technology was to build a filling body support platform in the middle of the roadway.The platform was supported by a single pillar with a filling bag on the platform,the top of the filling bag was hanging on the top plate of the roadway,the filler bag was free to face the barrier,the metal net,and the board(prevent filling bags from being bloated).Filling the bag with the air to fully fill the space,then fill the slurry with a high-speed pulper.After on-site experiment,the results show that the ultra-high retreating roadway uses a new type of grouting material to implement top filling technology supporting strength of single pillar is 12.3-25.7 MPa,high efficiency,effectively improve the integrity and stability of the top of the section roadway.