水平应力条件下矩形煤巷支护优化研究

发布时间：2018-06-07 14:51

本文选题：坚硬顶板 + 快速掘进　；参考：《昆明理工大学》2017年硕士论文

【摘要】：山东某煤矿3下煤埋深约800m,煤层属于厚煤层,水平应力大。煤层中裂隙、层理发育,局部有夹矸,煤质软、强度低、完整性差。由于回采需要将回采巷道设计为5×3.8m的大断面矩形煤巷,影响因素多,支护难度大。在矿井西部采区3下煤层厚度逐步变薄,其上多数为中砂岩顶板。但原支护参数不合理,没能利用坚硬顶板的良好条件去发展快速掘进,反而使坚硬顶板制约了掘进的速度,占用大量人员,工作效率低下,综合机械化掘进水平停滞在230～240米/月,严重影响了矿井的正常生产接续。本文针对3下煤层巷道掘进面临的以上问题,通过理论分析、数值模拟、现场监测等方法进行研究。(1)通过研究水平应力下巷道变形机理及水平应力下支护系统的破坏形式,发现水平应力作用下锚杆、锚索易发生剪切破坏,因此要求支护体有很好的抗剪能力,并且巷道支护要采用“先控顶,后护帮”的支护策略。(2)通过FLAC3D软件模拟,研究水平应力场中层理面对矩形煤巷应力分布的影响,以及水平应力场中层理面和夹矸对矩形煤巷围岩稳定性的影响。发现层理面在受到剪切破坏后,会发生相对的滑移,导致水平应力更多的作用于煤壁,所以离层理面越近塑性区深度越大。夹矸的厚度、硬度都会对巷道的稳定性产生影响,薄层软弱夹矸最不利于巷道的稳定。(3)通过研究大间排距支护理论,对现支护参数进行优化以实现水平应力场中大跨度矩形煤巷的大间排距支护。当顶板较硬导致锚杆施工困难时,可以通过适当增加锚杆的长度,提高预紧力,使用高强度的锚杆实现巷道的大间排距支护。利用FLAC3D软件模拟巷道的不同支护方式选出最优方案。根据巷道掘进反馈的矿压监测数据,对模拟结果进行验证,证明数值模拟的结果有一定的参考意义。(4)根据巷道掘进反馈的矿压监测数据,对支护参数的优化进行反馈和评价。通过优化巷道支护参数、施工工艺和施工工序,综掘单进达到400～450米/月,并具备500米/月以上的能力。
[Abstract]:The depth of coal buried in No. 3 coal mine in Shandong province is about 800 m.The coal seam belongs to thick coal seam, and the horizontal stress is large. Coal seam fractures, bedding development, local gangue, soft coal, low strength, poor integrity. Because of the need to design the large section rectangular coal roadway with 5 脳 3.8m, there are many influencing factors and the support is difficult. In the west mining area of the mine, the thickness of coal seam 3 is gradually thinning, and most of the upper coal seam is middle sandstone roof. However, the original support parameters are unreasonable and can not use the good conditions of hard roof to develop rapid tunneling. On the contrary, the hard roof restricts the speed of tunneling, occupies a large number of personnel, and has low working efficiency. The level of comprehensive mechanized tunneling has stagnated at 230 ~ 240 m / month, which has seriously affected the normal production of the mine. In this paper, aiming at the above problems faced by roadway driving in three coal seams, through theoretical analysis, numerical simulation, field monitoring and other methods, this paper studies the mechanism of roadway deformation under horizontal stress and the failure form of support system under horizontal stress. It is found that the bolt is prone to shear failure under horizontal stress, so it is required that the supporting body have good shear resistance, and the roadway support should adopt the support strategy of "controlling the roof first, then protecting the slope" by means of FLAC3D software. The influence of bedding in horizontal stress field on the stress distribution of rectangular coal roadway and the influence of bedding surface and gangue in horizontal stress field on the stability of surrounding rock of rectangular coal roadway are studied. It is found that the relative slip of the bedding surface will occur after shear failure, which leads to more horizontal stress acting on the coal wall, so the depth of the plastic zone near the bedding surface is greater. The thickness and hardness of gangue will affect the stability of roadway. The parameters of existing support are optimized to realize large spacing support of large span rectangular coal roadway in horizontal stress field. When the roof is hard and the bolt is difficult to be constructed, it can be used to support the roadway with large spacing by increasing the length of the bolt and increasing the pretightening force. FLAC3D software is used to simulate the different supporting ways of roadway to select the optimal scheme. According to the mine pressure monitoring data of roadway tunneling feedback, the simulation results are verified, and it is proved that the numerical simulation results have certain reference significance. (4) according to the mine pressure monitoring data of roadway tunneling feedback, the optimization of support parameters is feedback and evaluation. By optimizing the supporting parameters, construction technology and construction procedure, the single entry of fully mechanized excavation can reach 400 ~ 450m / month and has the capability of more than 500m / month.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD353

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