硐室群下大巷煤柱旋转开采覆岩运动规律研究

    Research on the movement law of overburden strata during rotary mining of coal pillars in the main roadway under a chamber group

    • 摘要: 针对深部硐室群下大巷煤柱工作面旋转开采时,大巷煤柱受近邻硐室群及自身旋转等多重因素综合影响,面临顶板稳定性控制与回采巷道支护困难等难题。本文以山东省某矿2317工作面为背景,通过理论分析、数值模拟和现场监测,研究了硐室群对下位大巷煤柱工作面上覆岩层及巷道围岩稳定性的影响,以及硐室群下大巷煤柱旋转开采覆岩运动规律,得到硐室群周边发生应力重组,距离较近硐室会形成塑性贯通区,由于岩层较为稳定且距离工作面较远对大巷煤柱工作面上覆岩层影响较小,巷道较为稳定;随着工作面不断旋采,旋转角增大,采场覆岩最大位移位置分布存在不对称性,回采巷道围岩位移呈增大趋势;当工作面旋采推进至煤仓硐室群下时,煤仓底部与工作面顶板塑性贯通,发生屈服破坏,需加强顶板管控。揭示硐室群下大巷煤柱工作面旋转开采覆岩运动规律及围岩变形特征,为硐室群下大巷煤柱安全高效开采提供理论支持。

       

      Abstract: Rotary mining conducted on the main roadway coal pillar’s working face under a deep chamber group is influenced by various factors, including neighboring chamber groups and the pillar’s rotation. This situation presents challenges in maintaining roof stability and supporting the mining roadway. This study focuses on the 2317 working face of a mine in Shandong Province. By employing theoretical analysis, numerical simulation, and on-site monitoring, the impact of the chamber group on the stability of the overburden strata and surrounding rock of the lower roadway coal pillar working face is investigated. Additionally, the movement patterns of the overburden strata during the rotary mining of the roadway coal pillar under the chamber group are examined. The study reveals stress recombination in the vicinity of the chamber group, leading to the formation of a plastic through zone near the chamber. The stability of the roadway is primarily attributed to the stable rock layer and the minimal impact of distance from the working face on the overburden strata of the roadway coal pillar. As the working face advanced and the rotary angle increased, asymmetry emerges in the distribution of maximum displacement position of the overburden strata within the mining area, with a noticeable increasing trend in surrounding rock displacement. Upon the progression of rotary mining to the base of the coal bunker chamber group, a plastic connection formed between the bottom of the coal bunker and the roof of the working face, leading to yield failure, necessitating enhanced control of the roof. This study aims to elucidate the movement patterns of overburden strata and the deformation characteristics of surrounding rock during the rotational mining of coal pillars in underground chamber groups, offering theoretical underpinning for the safe and efficient extraction of coal pillars in such settings.

       

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