锚固长度对巷道围岩支护作用的数值模拟研究

发布时间：2018-09-03 12:57

【摘要】：锚杆是煤炭生产中重要的支护构件,应用广阔,但是目前的锚杆加固理论对岩土支护机制还不完全明确,所用计算模型也是大量简化过的,所以理论、计算方法都不够精确,在定量计算锚杆支护方面存在严重缺陷,只能在理论上解释,与实际的设计有很大误差。因为模型本身的缺点,锚杆加固的实际效果不能较好地表现出来,锚杆支护设计很多时候倾向于经验类比。岩土锚固理论的研究远远跟不上工程实践,束缚了锚杆支护技术的发展应用,甚至还会引起严重的工程事故。锚杆支护成功与否,在于锚杆支护的方法和参数是否有效,目前巷道安全控制亟待解决的问题便是如何保持围岩的稳定。因此,研究巷道锚杆支护具有特殊意义和实用价值,也是为巷道支护方式的选择及支护技术的发展提供合理判据的基础。明确锚固围岩失效机理、分析锚杆的锚固特性以及选取恰当的数值模拟计算方法都是研究锚杆锚固的重点。本文在已有试验、理论的基础上,通过数值模拟及现场试验的综合方法,探讨了巷道顶板、两帮锚固失效的原因,并对端头锚固锚杆,全长锚固锚杆的受力特点,锚固特性进行了分析,以单根和群锚两种形式数值模拟了端头锚固、加长锚固以及全长锚固的支护作用。通过对模拟结果对比发现全长锚固的支护效果相对较好,兼有端头锚固的优点,增加了对围岩离层及错动的敏感度。在顾桥矿区进行井下工业性试验,对全长锚固状态下锚杆受力以及移动变形情况进行了监测。矿压监测数据表明：全长锚固锚杆对岩体的支护是全面的,它不仅改善了锚杆的支护效果,而且还保障了巷道岩体的稳定性,能有效控制围岩变形,相对更有市场发展性。
[Abstract]:Anchor rod is an important supporting component in coal production, which is widely used, but the current bolting reinforcement theory is not completely clear about the supporting mechanism of rock and soil, and the calculation model used is also a large number of simplified, so the theory and calculation method are not accurate enough. There are serious defects in quantitative calculation of bolting support, which can only be explained in theory and have great error with the actual design. Because of the shortcomings of the model itself, the actual effect of bolting reinforcement can not be shown well, and the design of bolt support tends to be empirically analogous. The study of rock and soil anchoring theory is far from keeping up with engineering practice, which restrains the development and application of bolt support technology, and even causes serious engineering accidents. The success of bolt support depends on whether the method and parameters of bolt support are effective or not. At present, the problem of roadway safety control is how to maintain the stability of surrounding rock. Therefore, it is of special significance and practical value to study roadway bolting support, and it is also the basis of providing reasonable criterion for the choice of roadway support mode and the development of supporting technology. It is important to determine the failure mechanism of anchoring surrounding rock, to analyze the anchoring characteristics of anchor rod and to select appropriate numerical simulation method. On the basis of existing tests and theories, through numerical simulation and field test, this paper discusses the reasons for the failure of roof and two side anchoring of roadway, and analyzes the mechanical characteristics of the anchoring bolt at the end of the tunnel and the full-length anchoring bolt. The Anchorage characteristics are analyzed and the support effects of end Anchorage, extended Anchorage and Full-length Anchorage are numerically simulated by single anchor and group anchor. Through the comparison of simulation results, it is found that the full length anchoring has relatively good support effect and has the advantages of end anchoring, which increases the sensitivity to the surrounding rock separation and dislocation. A downhole industrial test was carried out in Guqiao mining area to monitor the stress and deformation of the anchor rod under the state of full-length anchoring. The monitoring data of rock pressure show that the full length anchor bolt is comprehensive in supporting rock mass, which not only improves the support effect of bolt, but also ensures the stability of rock mass of roadway, and can effectively control the deformation of surrounding rock, and is relatively more marketable.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353

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