高级检索

迎采工作面沿空掘巷围岩能量−应力全周期演化规律

The full cycle evolution law of energy-stress in the surrounding rock of the gob-side entry driving for adjacent advancing working face

  • 摘要: 迎采动工作面沿空掘巷经历上工作面侧向基本顶断裂、回转、下沉全过程的全周期动压影响,巷道变形量大、维护困难。本文以温庄煤矿15105工作面为工程背景,提出在原有25 m煤柱迎采动面掘巷的基础上,沿上工作面非稳定采空区后方改变巷道掘进轨迹,将区段煤柱宽度减小至6 m,进行沿空掘巷。为了证明方案的可行性,采用FLAC3D建立数值模型,模拟了原方案与优化方案2种情况下的巷道围岩能量−应力全周期(迎15103采动工作面掘进、非稳定采空区侧巷道掘进、15105工作面回采)演化规律。模拟结果显示:① 迎15103采动工作面掘进期间,应力和能量主要集中在区段煤柱的采空区侧。② 非稳定采空区侧巷道掘进期间,与原方案相比,优化方案使6 m煤柱内部能量和应力转移至工作面煤体侧。③ 15105工作面回采期间,采取原方案时,能量和应力均向25 m煤柱回采侧集中,应力峰值达到31.2 MPa,最大能量为192.4 kJ/m3;采取优化方案时,能量和应力均向工作面实体煤侧转移,6 m煤柱具备一定承载能力,并且整个过程中应力集中程度低、能量无明显聚集,回采期间6 m煤柱内部应力峰值仅8.1 MPa,最大能量为126.7 kJ/m3。在此基础上,确定了优化方案的可靠性,并结合数值模拟结果和现场地质条件,提出将巷道分成4个区段:迎采对掘段、临空掘巷段、渐变煤柱段和沿空掘巷段,建立了巷道围岩分区控制体系,设计了锚杆、索支护参数。最终成功开展了工业性实验,现场监测结果显示各区段巷道整体控制效果良好。

     

    Abstract: The full cycle dynamic pressure impact of the lateral basic roof fracture, rotation, and sinking of the upward working face along the gob excavation roadway in the face of mining is significant, and the roadway deformation is difficult to maintain. This article takes the 15105 panel of Wenzhuang Coal Mine as the engineering background, and proposes to change the excavation trajectory of the roadway behind the unstable gob of 15103 panel, on the basis of the original 25 m coal pillar facing the gob, and reduce the width of the section coal pillar to 6 m for gob excavation. In order to demonstrate the feasibility of the plan, a numerical model was established using FLAC3D to simulate the evolution law of the energy stress full cycle of the surrounding rock of the roadway (driven heading for mining of 15103 panel, excavation of the unstable gob side roadway, and mining of the 15105 panel) under two scenarios: the original plan and the optimized plan. The simulation results show that: ① During driven heading for mining of 15103 panel, stress and energy are mainly concentrated on the gob side of the section coal pillar. ② During the excavation of the unstable gob side roadway, compared with the original plan, the optimized plan transferred the internal energy and stress of the 6 m coal pillar to the coal body side of the working face ③ During the mining period of the 15105 panel, when adopting the original plan, both energy and stress were concentrated towards the mining side of the 25 m coal pillar, with a peak stress of 31.2 MPa and a maximum energy of 192.4 kJ/m3. When adopting the optimization plan, both energy and stress are transferred to the solid coal side of the working face. The 6 m coal pillar has a certain bearing capacity, and the stress concentration is low and there is no obvious energy accumulation throughout the process. During the mining period, the peak stress inside the 6 m coal pillar is only 8.1 MPa, and the maximum energy is 126.7 kJ/m3. On this basis, the reliability of the optimization plan was determined, and combined with numerical simulation results and on-site geological conditions, it is proposed to divide the roadway into four sections: the face to face mining section, the gob excavation section, the gradient coal pillar section, and the gob excavation section. A zoning control system for the surrounding rock of the roadway was established, and anchor bolt support parameters were designed. Finally, industrial experiments were successfully conducted, and on-site monitoring results showed that the overall control effect of each section of the roadway was good.

     

/

返回文章
返回