【作者】 董健涛；

【导师】 缪协兴；

【作者基本信息】 中国矿业大学 ， 工程力学， 2009， 博士

【摘要】 锚网索支护对确保巷道围岩的稳定性、简化采面端头工序等具有重要作用。但是,由于锚网索组合支护作用,切眼和端头后方顶板不能随采面推进及时冒落,引起切眼和工作面端头后方较大范围的悬顶,从而造成一系列的安全隐患。首先,工作面端头后方较大范围的悬顶,形成通风死角和向采空区漏风等严重安全隐患;其次,在切眼处和采空区两侧煤柱中形成较大的支承压力,使煤柱的稳定性受到减弱,并影响邻近巷道围岩的稳定性,使邻近巷道维护困难。本文综合运用理论分析、数值模拟和现场观测等方法对锚网索支护解除的力学机理及方法等进行了系统研究,取得了如下主要研究成果:(1)探讨了锚网索支护对围岩的加固机理,研究了锚网索支护解除前后顶板围岩形态以及对通风安全的影响,从理论上分析了锚网索解除使组合梁及悬吊作用失效的力学机理及弧形三角块结构的稳定性特征,得到了锚网索支护解除对采空区两侧悬顶及时冒落的影响规律。(2)建立了锚网索支护解除对煤柱支承压力影响分析的Winkler弹性地基梁模型,分析了锚网索支护解除对煤柱支承压力的影响及煤柱屈服区的变化特征,得到了煤柱支承压力随巷道悬顶长度的变化规律及煤柱屈服区大小随煤柱强度、悬顶长度的变化规律。(3)借助于数值模拟方法,分析了锚网索支护解除对煤柱和邻近巷道围岩稳定性的影响,研究表明:煤柱支承压力随悬顶长度的减小而减小,煤柱的稳定性随锚网索支护解除而得到加强;邻近巷道顶板下沉量、两帮移近量及底鼓量随悬顶长度的减小而显著下降,巷道围岩的稳定性随锚网索支护解除而得到提高。(4)在对锚杆支护机理分析的基础上,考虑到后期锚杆支护解除的要求,研制设计了新型树脂式可回收锚杆的结构,并进行了井下试验。结果表明:新型可回收锚杆对软岩和煤层巷道具有良好的适应能力,且安装回收方便,为锚杆支护解除技术的应用提供了保证。(5)初步开发了切眼和巷道锚网索支护解除技术,并应用于煤矿开采的生产实践。经现场观测试验表明,工作面两端和切眼等锚网索支护解除后,顶板能够及时垮落,工作面顶板管理、采空区漏风等安全隐患问题得到有效解决,邻近巷道围岩的应力集中程度得到明显缓解,巷道围岩变形得到有效控制,取得了显著的经济和社会效益。更多还原

【Abstract】 Bolt-mesh-cable support has an important role on ensuring the stability of tunnel surrounding rock, simplifying end processes of mining face, etc. However, due to combination of bolt-mesh-cable supporting role, cut hole and end backside roof can not timely collapse with the mining face advance, causing a large range of hanging roof of cut hole and end backside, resulting in a series of safety problems. First of all, the large range of hanging roof on mining face end backside form ventilation dead angle and leak air to mined-out area and other serious safety problems; Secondly, larger bearing pressure of coal pillar near cut hole and both sides of mined-out area is formed, which weakens of coal pillars stability and affect the stability of adjacent roadway surrounding rock, makes adjacent roadway maintenance problems. With comprehensive use of theoretical analysis, numerical simulation and site observation, the systematic study of the mechanism and methods of bolt-mesh-cable release was performed, the main research achievements are as follows:(1) Surrounding rock reinforcement mechanism of bolt-mesh-cable support was explored, the roof rock patterns before and after bolt-mesh-cable release as well as impact on ventilation safety were studied, failure mechanism of composite beam and suspension role and characteristics of curved triangular block stability of bolt-mesh-cable was theoretically analyzed, bolt-mesh-cable release impact laws to mined-out area both side hanging roof timely collapse has been gained.(2) Winkler elastic foundation beam model for bolt-mesh-cable release impact analysis to coal pillar bearing pressure is established, the bolt-mesh-cable release impact to coal pillar bearing pressure and changing characteristics of coal pillar yield zone are analyzed, laws of coal pillar bearing pressure change with hanging roof length as well as coal pillar yield zone size change with coal pillar strength and hanging roof length are obtained.(3) By means of numerical simulation method, bolt-mesh-cable release impact to coal pillar and adjacent roadway surrounding rock stability is analyzed, studies shows that: coal pillar bearing pressure and yield zone size decreases with the length of hanging roof decreases, coal pillar stability is strengthened with bolt-mesh-cable release; adjacent roadway roof sinking amount, two side displacement and floor heave significantly decreased with the hanging roof length reduced, roadway surrounding rock stability is improved with bolt-mesh-cable release. (4) Based on analysis of bolting mechanism, considering the requirements of later stage bolt release, a new type of resin retrievable bolt structure was developed and designed, and underground tests was carried out. The results shows that: the new retrievable bolt has a good ability to adapt soft rock and coal seam roadway, and is convenient to install and recycling, provides a guarantee for bolt release technology application.(5)Cut hole and roadway bolt-mesh-cable release technology was initially developed, and applied to coal mining practices. The field observation experiments show that the roof can timely collapse, mining face roof management and mined-out area air leakage and other safety problems are effectively solved, adjacent roadway surrounding rock stress concentration has been markedly alleviated, roadway surrounding rock deformation has been effectively controlled, and achieved remarkable economic and social benefits.更多还原