极近距离煤层开采巷道优化布置及支护技术研究

发布时间：2018-04-29 12:42

本文选题：底板损伤 + 采空区　；参考：《中国矿业大学》2016年硕士论文

【摘要】：针对极近距离下部煤层回采巷道布置及支护的重大技术难题,应用理论分析、数值模拟和工程验证等综合手段,研究了底板损伤破坏深度计算方法并利用数值模拟进行了验证,确定了稳定煤柱的临界宽度,并通过数值模拟分析了煤柱稳定性,同时对比分析了单侧采空和双侧采空时煤柱底板应力分布,进一步深入分析了不同煤柱宽度底板应力分布规律。结合前面分析的应力规律,确定了下煤层回采巷道的布置原则,给出了采空区和稳定煤柱下方回采巷道合理位置的确定方法。最后分析了采空区下和煤柱下巷道变形失稳的机理,提出了“三高”锚杆支护技术、预应力锚索桁架支护技术以及松散破碎岩层全长锚固技术,得出的主要结论如下:(1)建立了采场应力计算模型,综合运用弹塑性理论、滑移线理论计算公式,得出杜儿坪矿8号煤开采后的底板最大损伤破坏深度为32m,同时利用数值模拟分析了采高和埋深对于底板损伤的影响。(2)结合杜儿坪矿工程地质条件分析了杜儿坪遗留区段煤柱的稳定性,运用公式计算得出了杜儿坪稳定煤柱的临界宽度为15.5~19m,杜儿坪矿68301和68302工作面的遗留区段煤柱均为稳定性煤柱,并通过数值模拟加以验证,综合得出杜儿坪稳定煤柱的临界宽度为15m。(3)通过数值模拟分析了单侧采空和双侧采空情况下煤柱底板应力分布规律,同时进一步研究了不同煤柱宽度、采高、埋深、层间距、岩性情况下煤柱底板应力分布规律,结合煤柱底板应力分布规律,确定了煤层回采巷道合理位置的确定方法。当层间距小于1.5m时,巷道优先布置在煤柱下,当层间距不小于1.5m时,巷道优先布置在采空区下。针对采空区下回采巷道布置位置,提出将回采巷道布置在应力降低区和应力均匀区,从而确定回采巷道具体内错位置;针对煤柱下回采巷道布置位置,提出了煤柱下巷道布置要尽可能远离应力峰值区,布置在应力集中程度尽可能低的区域,给出了不同煤柱宽度下煤柱下巷道的外错位置。(4)针对采空区下巷道顶板失稳规律提出了预应力锚索桁架支护技术和松散破碎岩层全长锚固技术,从而构建顶板楔形整体加固区,利于采空区下巷道的维护。针对煤柱下巷道围岩应力高、非对称变形和后期变形突出三个变形特征,提出了非对称支护设计和大加固圈围岩控制思想的控制手段。69301正巷和付巷掘进期间的矿压规律表明巷道布置位置和支护方案合理,满足了工程要求。
[Abstract]:In view of the important technical problems of roadway layout and support in the coal seam of very close distance lower coal seam, the method of calculating the damage and failure depth of floor plate is studied and verified by numerical simulation, using the comprehensive means of theoretical analysis, numerical simulation and engineering verification. The critical width of the stable pillar is determined, and the stability of the pillar is analyzed by numerical simulation. The stress distribution law of different coal pillar width floor is further analyzed. Combined with the stress law of the previous analysis, the layout principle of the mining roadway in the lower coal seam is determined, and the method of determining the reasonable position of the stoping roadway under the goaf and the stable coal pillar is given. Finally, the mechanism of deformation and instability of roadway under goaf and coal pillar is analyzed, and the "three high" anchor support technology, pre-stressed anchor cable truss support technology and full-length anchoring technology of loose broken rock are put forward. The main conclusions are as follows: (1) the stress calculation model of stope is established, and the elastoplastic theory and slip line theory are used to calculate the stress. It is concluded that the maximum damage depth of floor after mining of No. 8 coal in Duerping Coal Mine is 32 m, and the influence of mining height and buried depth on floor damage is analyzed by numerical simulation. 2) combined with engineering geological conditions of Duerping Mine, the legacy of Duerping Mine is analyzed. Stability of coal pillar in section, The critical width of Duerping stable coal pillar is 15.519 m, and the remaining sections of 68301 and 68302 face of Duerping Coal Mine are all stable pillars, which are verified by numerical simulation. It is concluded that the critical width of the stable coal pillar in Duerping is 15m.m3) the stress distribution law of the coal pillar bottom is analyzed by numerical simulation under the condition of unilateral and double-side caving, and the different coal pillar width, mining height, buried depth and interval between layers are further studied. Under the condition of lithology the stress distribution law of coal pillar floor is combined with the stress distribution law of coal pillar floor to determine the reasonable position of coal seam mining roadway. When the interval is less than 1.5 m, the roadway is arranged first under the coal pillar, and when the interval is not less than 1.5 m, the roadway is arranged first under the goaf. Aiming at the location of roadway layout under goaf, this paper puts forward that the roadway should be arranged in the area of stress reduction and uniform stress, so as to determine the specific position of inner dislocation of roadway, and the location of roadway layout under pillar. It is suggested that the roadway layout under the coal pillar should be as far away as possible from the peak stress area and be arranged in the area with the lowest degree of stress concentration. According to the instability rule of roadway roof in goaf, the pre-stressed anchor cable truss support technology and the full-length anchoring technology of loose broken rock layer are put forward, so as to construct the roof wedge integral reinforcement area. It is beneficial to the maintenance of the roadway under the goaf. Aiming at the three deformation characteristics of roadway under coal pillar, such as high stress, asymmetric deformation and late deformation, This paper puts forward the control means of asymmetric support design and surrounding rock control of large reinforcement ring. The rule of rock pressure in the period of tunneling of main roadway 69301 and Fu roadway shows that the layout of roadway and the supporting scheme are reasonable and meet the requirements of engineering.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD353

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