【作者】 刘坤；

【导师】 栾恒杰； 刘建荣；

【作者基本信息】 山东科技大学 ， 资源与环境（专业学位）， 2025， 硕士

【摘要】 厚煤层沿空巷道往往承受较大的采动应力,导致巷道围岩极易发生变形破坏,尤其是当受到相邻采空区的水火瓦斯等威胁时,确定合理的煤柱尺寸及巷道支护方案,对于煤矿安全高效开采至关重要。本文针对复杂采空区条件下浅埋厚煤层沿空巷道的围岩控制技术难题,以牙星煤矿427工作面为研究对象,综合运用理论分析、数值模拟、室内试验与现场实测等手段,系统开展了煤柱宽度优化、支护方案设计等研究,并取得以下主要成果:(1)开展了巷道围岩地质力学评估,结果表明:煤的单轴抗压强度24.95 MPa,顶底板岩石的单轴抗压强度分别为43.07 MPa和40.67 MPa;最大水平主应力3.59 MPa(方向N44.1°E),垂直主应力7.25 MPa;427运输顺槽顶板松动圈最大2.0 m、帮部1.8～1.9 m,轨道顺槽松动圈最大1.9 m,围岩整体稳定性良好。(2)研究了煤柱宽度对围岩应力分布、塑性区演化及变形特征的影响规律。基于极限平衡理论建立了采空区侧向塑性区力学模型,推导了煤柱塑性区宽度的理论解,并结合锚杆锚固需求提出煤柱合理宽度。结合FLAC3D模拟开展宽度敏感性分析,结果表明:当煤柱宽度为8 m时,围岩塑性区收敛,应力分布合理,巷道稳定性良好,锚固条件优越。综合考虑煤柱承载能力、锚固支护有效性及采空区灾害隔离要求,提出8 m为合理煤柱宽度,该方案在保障巷道稳定的同时实现了资源高效回收。(3)在FLAC3D中引入锚杆应变硬化本构模型,构建改进数值模型对支护系统进行模拟。结果显示:巷道顶板最大下沉量控制在501 mm内,帮部最大移近量约400 mm,围岩塑性区范围稳定于1.5 m以内;锚杆与锚索轴力稳定在20 k N与38.6 k N,支护系统与围岩形成良好协同受力体系,验证了支护参数的合理性与控稳效果。(4)结合自然平衡拱理论与锚固机理,确定了锚杆锚索支护参数:顶锚杆长2400 mm、帮锚杆长1600～2400 mm,锚杆间排距800 mm×1000 mm;顶锚索长6000 mm,间排距1500mm×3000 mm。通过锚固力计算与工程类比校核,确保了结构承载能力及施工适应性,为巷道在复杂应力环境下的长期稳定提供了技术保障。(5)在427工作面布设测站,开展巷道变形、顶板离层及锚杆(索)受力全过程监测。结果表明:最大顶板离层量小于25 mm,巷道断面稳定无明显失稳迹象;锚索轴力最大达249 k N,增长速率达10.41 MPa/m,支护系统能有效适应回采扰动,维持围岩稳定。本研究成果为复杂采空区条件下浅埋厚煤层沿空巷道回采巷道支护优化提供了理论依据与工程支撑,对类似地质条件下的矿井巷道布置及围岩控制具有重要的示范与推广价值。更多还原

【Abstract】 The gob-side roadway in thick coal seam is often subjected to large mining stress,resulting in the roadway surrounding rock is very easy to deformation and damage,especially when threatened by water,fire,and gas from the adjacent goaf.Determining the reasonable size of the coal pillar and the roadway support program is crucial for the safe and efficient mining of coal mines.Aiming at the technical problems of controlling the of surrounding rock control technology for shallow-buried thick coal seam gob-side roadway under complex goaf conditions,this thesis takes 427 working face of Yaxing Coal Mine as the research object,and systematically carries out the research of optimizing of coal pillar width and designing of support scheme by comprehensively applying the means of theoretical analyses,numerical simulations,indoor experiments and on-site measurements,and achieves the following main results:(1)Geomechanical assessment of roadway surrounding rock was conducted.Results indicate that the uniaxial compressive strength of coal,overlying and underlying strata is 24.95 MPa,43.07MPa and 40.67 MPa,respectively.The maximum horizontal principal stress measures 3.59 MPa(N44.1°E orientation),while vertical principal stress reaches 7.25 MPa.The loosening circle of the top of 427 transportation roadway is 2.0 m,that of the gang part is 1.8～1.9 m,and the loosening circle of the railroad track roadway is 1.9 m at the most,and the overall stability of the roadway surrounding rock is good.(2)The influence laws of coal pillar width on the stress distribution of surrounding rock,the evolution of plastic zone and the deformation characteristics were studied.Based on the limit equilibrium theory,a lateral plastic zone mechanical model of the goaf was established,the theoretical solution of the width of the coal pillar plastic zone was derived,and the reasonable width of the coal pillar was proposed in combination with the anchor bolt anchoring requirements.Width sensitivity analysis was carried out based on FLAC3D simulation,and the results show that when the coal pillar width is 8 m,the plastic zone of the surrounding rock converges,the stress distribution is reasonable,the stability of the roadway is good,and the anchoring conditions are superior.Considering the bearing capacity of the coal pillar,the effectiveness of anchor support,and the requirements for isolation of the goaf disaster,8 m is proposed as the reasonable coal pillar width.This scheme ensures the stability of the roadway while achieving efficient recovery of resources.(3)The constitutive model of anchor bolt strain hardening was introduced into FLAC3D,and an improved numerical model was constructed to simulate the supporting system.The results show that the maximum subsidence of the roadway roof is controlled within 501 mm,the maximum displacement of the side is about 400 mm,and the plastic zone of the surrounding rock is stable within 1.5 m;the axial force of the anchor bolt and anchor cable is stable at 20 k N and 38.6 k N respectively,and the supporting system and surrounding rock form a good coordinated force-bearing system,verifying the rationality and control effect of the supporting parameters.(4)By integrating the theory of natural balanced arch and the anchoring mechanism,the supporting parameters of anchor bolts and anchor cables were determined:the top anchor bolt is2400 mm long,the side anchor bolts are 1600-2400 mm long,and the spacing between anchor bolts is 800 mm×1000 mm;the top anchor cable is 6000 mm long,and the spacing between anchor cables is 1500 mm×3000 mm.Through anchoring force calculation and engineering analogy verification,the structural bearing capacity and construction adaptability were ensured,providing technical support for the long-term stability of the roadway under complex stress conditions.(5)Measuring stations were set up in the 427 working face to conduct full-process monitoring of roadway deformation,roof spalling and anchor bolt(cable)force.The results show that the maximum roof spalling is less than 25 mm,and there are no obvious signs of instability in the roadway section;the maximum anchor cable axial force reaches 249 k N,and the growth rate is10.41 MPa/m,the supporting system can effectively adapt to the disturbance caused by mining,and maintain the stability of the surrounding rock.This research establishes theoretical frameworks and engineering solutions for gob-side entry support optimization in shallow-buried thick coal seams,offering demonstrative value for roadway layout and surrounding rock control in analogous geological conditions.更多还原