羊拉铜矿破碎软岩巷道支护优化及其稳定性研究

发布时间：2018-02-10 05:51

本文关键词： 岩石力学破碎软岩支护优化稳定性失稳机理数值模拟经济效益　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：羊拉铜矿位于云南德钦县羊拉乡,该矿3390中段围岩松散破碎巷道支护困难,为解决该矿软岩巷道的支护问题,进行了现场调查和室内试验研究,研究成果对该矿的正常生产有重要意义,对其他软岩工程支护也具有参考价值。通过现场调查、室内岩石力学试验、矿物成分分析、水理试验、风化试验、自由膨胀率试验,分析得出导致巷道失稳的原因主要是矿岩本身强度低,结构面发育,岩体结构松散破碎;其次是支护形式选择不当或者未能及时支护、封闭,水、风化作用、干湿循环效应对围岩的弱化;再次是围岩应力状态的改变对巷道围岩抗剪强度的不利影响。通过巷道失稳机理的分析,提出了能封闭围岩的锚网喷支护方案,应用弹塑性理论计算出了巷道的塑性软化区的半径为2.94m,并基于松动圈理论和锚杆的悬吊理论提出了优化的支护方案。采用离散元软件3DEC模拟了采动影响前后不支护、衬砌和锚网支护的稳定情况。模拟结果显示:采动前三种支护的两帮相对收敛率分别为4.71%、1.35%、2.03%;顶底板相对收敛率分别为4.55%、1.60%、1.80%。采动后三种支护的两帮相对收敛率分别为8.68%、1.87%、3.62%,顶底板相对收敛率分别为8.51%、2.58%、3.45%。不支护采动前后相对收敛率均超过最大允许值4%,巷道不稳定,优化的锚网喷支护方案在采动前后相对收敛率均小于最大允许值4%,方案可行。模拟结果还显示采动前后,围岩中最大拉、压应力均小于允许值,巷道稳定。最后对锚网喷和衬砌支护进行经济效益比较,得出每米支护成本锚网喷比衬砌支护低1288.4元,因此,从支护效果和经济效益两方面综合评价,锚网喷支护方案更优。
[Abstract]:Yangla Copper Mine is located in Yangla Township of Deqin County, Yunnan Province. It is difficult to support loose and broken roadway in the middle part of 3390 mine. In order to solve the support problem of soft rock roadway in this mine, field investigation and laboratory test are carried out. The research results are of great significance to the normal production of the mine, and also have reference value to other soft rock engineering support. Through field investigation, indoor rock mechanics test, mineral composition analysis, hydrological test, weathering test, free expansion rate test, It is concluded that the main causes of roadway instability are the low strength of the rock itself, the development of the structural plane, the loosely broken rock mass structure, the improper selection of the supporting form or the failure to support in time, the sealing, the water and the weathering. The dry and wet circulation effect weakens the surrounding rock, and the change of the stress state of the surrounding rock affects the shear strength of the surrounding rock of the roadway. Through the analysis of the mechanism of roadway instability, the paper puts forward the bolt-mesh shotcreting support scheme which can close the surrounding rock. Using elastoplastic theory, the radius of the plastic softening zone of roadway is calculated to be 2.94 m, and based on the loose ring theory and the suspension theory of anchor rod, the optimized support scheme is put forward. The discrete element software 3DEC is used to simulate the unsupporting before and after mining. The results of simulation show that the relative convergence rates of the three types of support before mining are 4.71 and 1.35 and 2.03, respectively, and the relative convergence rates of the top and bottom plates are 4.55 and 1.60 and 1.80 respectively. The relative convergence rates of the two supports after mining are 8.681.87 and 3.62respectively. The relative convergence rates of top and bottom plates are 8.51 and 2.58 / 3.45.The relative convergence rates before and after unsupported mining are above the maximum allowable value of 4 and the roadway is unstable, The relative convergence rate of the optimized bolt-net-shotcrete support scheme before and after mining is less than the maximum allowable value of 4, and the scheme is feasible. The simulation results also show that the maximum tensile stress and compressive stress in surrounding rock before and after mining are all less than the allowable value. The roadway is stable. Finally, the economic benefits of bolt-mesh shotcreting and lining support are compared, and it is concluded that the bolt-net shotcreting cost per meter is 1288.4 yuan lower than that of lining support. Therefore, the bolting net shotcreting scheme is better in terms of comprehensive evaluation of supporting effect and economic benefit.
【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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