特厚煤层巷道拱梁耦合支护结构与围岩稳定性控制研究

发布时间：2018-03-10 18:38

本文选题：特厚煤层　切入点：高预应力锚固体　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：特厚煤层巷道围岩强度低,巷道变形大,稳定性差,支护难度大,因此合理确定该类巷道的支护参数和对其稳定性进行研究至关重要。本论文研究课题以山西省自然科学基金“特厚煤层巷道高预应力锚固体结构特征及其稳定性控制研究”和校企合作项目“兴县金地煤业巷道支护优化研究”为背景,通过理论分析、数值模拟与工程实测分析相结合的方法,研究了特厚煤层巷道支护结构和围岩的稳定性控制对策。主要研究结论如下:(1)特厚煤层巷道顶板围岩强度低、裂隙发育,在顶板浅部及煤岩分界线下存在大量破碎带,不稳定煤体累计厚度达8m以上,悬吊点不明或不存在,对此类巷道的控制关键在于锚索的布局和其高预应力承载特性的发挥。特厚煤层拱梁耦合支护结构的形成,浅部组合梁结构能在有效控制浅部变形同时促进深部承载拱的形成,并有效提高承载拱的承载,深部的承载拱对浅部组合梁有减压和减跨作用。二者相互配合、彼此适应,构成完善的特厚煤层巷道高预应力锚杆-索耦合支护系统,使巷道稳定性得以提升。(2)特厚煤层巷道支护结构影响因素分析表明,关键影响参数为锚杆-索预紧力和长度。预紧力过小时无法在顶板上方形成稳定的承载结构,过大时,容易造成锚杆锚索失效或破坏,造成结构失稳,合理的预紧力取值是锚杆60KN,锚索150KN,合理施加锚索预紧力可使锚杆组合梁的承载能力提高113.74%。合理增加锚杆锚索长度有助于增大承载结构范围,但锚杆、索长度过大则会使围岩承载增加不明显甚至下降,不利于发挥锚杆、索的主动支护作用,合理的锚杆长度为2.4m,锚索长度为8m。(3)通过特厚煤层巷道支护结构稳定性研究得出:对支护参数进行优化后组合梁、承载拱的作用范围分别增大17.71%和10.27%,承载分别增加64.36%和46.86%,优化方案可充分发挥锚杆、索的主动承载作用,显著提升支护结构的承载。通过对特厚煤层拱梁耦合支护巷道围岩稳定性分析得出:优化方案对围岩中水平、垂直应力集中现象有明显改善,高帮上下两巷角剪切应力集中程度分别降低10%和15%;巷道围岩顶底板移近量、两帮收敛量相对分别降低了42.1%和45.2%,围岩塑性区大幅减小;锚杆锚索支护结构的承载能力提升较为明显,提升幅度为17.5%-47.7%。(4)对13205巷锚杆(索)工作载荷和位移等监测显示:支护过程中锚杆受力提升了31.3%,锚索提升12.6%,顶板离层最大48.5mm,两帮移近量、顶板下层量最大分别为为48mm、61mm,由此表明特厚煤层巷道采用高预应力锚杆-索耦合支护结构时巷道保持稳定、围岩变形得到有效控制。
[Abstract]:The surrounding rock strength of the roadway is low, the roadway deformation is large, the stability is poor, and the support is difficult. Therefore, it is very important to reasonably determine the supporting parameters and study the stability of this kind of roadway. The structural characteristics and Stability of High Prestressed Anchorage body of roadway in extra thick Coal seam of Shanxi Province Natural Science Foundation. The background of the control research is "the study of roadway support optimization in Xingxian Jindi coal industry" and the project of cooperation between school and enterprise. Through theoretical analysis, numerical simulation and practical engineering analysis, the stability control measures of roadway supporting structure and surrounding rock in extra thick coal seam are studied. The main conclusions are as follows: 1) the roof wall rock strength of extra thick coal seam roadway is low. There are a large number of fractured zones in the shallow roof and coal rock boundary, the cumulative thickness of unstable coal body is more than 8 m, and the suspension point is unknown or non-existent. The key to the control of this kind of roadway lies in the layout of anchor cable and the exertion of its high prestress bearing characteristics. The formation of the coupling support structure of arch and beam in thick coal seam, the shallow composite beam structure can effectively control the shallow deformation and promote the formation of deep bearing arch. The deep bearing arch can reduce the pressure and reduce the span of the shallow composite beam. They cooperate with each other and adapt to each other, and form a perfect high prestressed bolt-cable coupling support system in the roadway of super thick coal seam. The analysis of the influencing factors of roadway support structure in extra thick coal seam shows that the key parameters are bolt-cable preload force and length. If the pre-tightening force is too small, the stable bearing structure can not be formed above the roof. It is easy to cause the failure or failure of the anchor cable and the instability of the structure. The reasonable pretightening force is 60 KN of anchor rod and 150 KN of anchor cable. The reasonable pretightening force of anchor cable can increase the bearing capacity of composite beam by 113.74.The reasonable increase of the length of anchor cable is helpful to enlarge the bearing structure range, but the anchor rod, If the length of cable is too large, the bearing capacity of surrounding rock will not be increased obviously or even decreased, which will be unfavorable to play the role of anchor rod and active support of cable. The reasonable length of bolt is 2.4 m, and the length of anchor cable is 8m.m3) by studying the stability of roadway support structure in extra thick coal seam, it is concluded that the composite beam can be optimized after supporting parameters are optimized. The action range of bearing arch is increased by 17.71% and 10.27 respectively, and the bearing capacity is increased by 64.36% and 46.86 respectively. The optimized scheme can give full play to the active bearing action of anchor rod and cable. By analyzing the stability of roadway supported by arch and beam coupling support in thick coal seam, it is concluded that the optimization scheme can obviously improve the phenomenon of horizontal and vertical stress concentration in surrounding rock. The shear stress concentration degree of the upper and lower roadways is reduced by 10% and 15, and the convergence of the top and bottom plates of the roadway is reduced by 42.1% and 45.2, respectively, and the plastic zone of the surrounding rock is greatly reduced. The load-bearing capacity of bolting and cable supporting structure is more obvious. The range of lifting is 17.5- 47.7.) the monitoring of the working load and displacement of anchor rod (cable) in 13205 lane shows that: during the supporting process, the stress of anchor rod has been increased by 31.3 points, the bolting cable has been raised 12.6mm, the maximum roof layer has been 48.5 mm, and the two sides have moved closer. The maximum amount of roof and lower layer is 48mm or 61mm respectively, which indicates that the roadway is stable and the deformation of surrounding rock is effectively controlled when the roadway adopts high prestressed bolt-cable coupling support structure.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD353

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