【作者】 黄靖龙；

【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】 由于锚杆支护显著的技术经济优越性,已成为矿井巷道等地下工程支护的主要形式。煤矿巷道锚杆的种类繁多,我国煤矿巷道锚杆以树脂粘结式锚杆居多。但是,近年来发展起来的新型机械式可回收端锚锚杆,具有锚固性能好、可回收、施工快速方便等优点,然而,其支护机理等尚缺乏全面的认识。本文运用理论分析、实验测试、数值模拟和现场工业试验等方法与手段,对新型机械式可回收端锚锚杆支护的力学机理等进行了系统的研究,取得了如下创新性成果:(1)在详细考察新型机械式可回收端锚锚杆结构特点的基础上,对该新型锚杆的受力特征进行了系统的分析,对其力学性能进行了全面测试,并分析得到了锚固力的估算公式。在与树脂锚杆锚固性能比较的基础上,给出了该新型锚杆的适用环境。(2)针对锚杆支护的受力特点,建立了锚固围岩应力与变形分析的简化力学模型,并借助于经典弹性理论的Boussinesq解和Mindlin解,首次得到了锚固围岩应力场的解析解;给出了锚固围岩轴向、径向和环向应力的分布规律及随锚固长度的变化规律,揭示了端锚锚杆的锚固性能优于树脂锚杆的力学机理。(3)采用数值模拟方法,系统研究了锚固围岩沿锚杆的轴向应力、垂直于锚杆的径向应力和等效应力的分布特征,应用应力强度理论分析给出了不同锚固长度情况下锚杆支护对围岩强度的影响规律;研究结果表明,机械式端锚锚杆对锚固围岩的强化作用程度相对较高、强化作用范围相对较大。(4)系统研究了锚杆支护对巷道围岩稳定性的作用效应,给出了巷道围岩应力、变形、塑性区范围等随锚固长度和时间的变化规律,得到:随锚杆锚固长度的减小,巷道围岩的类压拱作用效应明显增强;巷道的顶底板移近量、两帮移近量均有明显减少;控制巷道围岩流变形的能力加强。(5)现场工业性试验,系统监测了新型机械式可回收端锚锚杆的支护效果,验证了该新型锚杆支护下的围岩稳定性和杆体的可回收性。监测结果表明,和同规格的树脂锚杆相比,新型机械式可回收端锚锚杆具有更优良的支护性能。研究成果可为新型机械式可回收端锚锚杆的推广应用提供重要依据。更多还原

【Abstract】 Bolt support has been the main support form of the mine roadway in the under- ground engineering because of its obvious technical and economical superiority. The bolt types are various in coal mine roadway support. Different kinds of bolts have different anchorage performances and different applicable conditions. Resin bolts are dominant in the coal mine roadway support bolts in China. The new type mechanical reusable end-anchored bolt developed recent years has some merits, such as good anchorage performance, the reuse of bolt and quick fixing . However, there is lack of all-round understanding about the support mechanisms of the new type mechanical reusable end-anchored bolt. In this paper, A synthetically study means combined with theoretical analysis, experimental test, numerical simulation and industrial field test is applied to study systematically the mechanical mechanism of the support of the new type mechanical reusable end-anchored bolt. And the study results with innovative significance are shown in the following:(1) Based on the detail study on the structure characteristics of the new type mechanical reusable end-anchored bolt, the stress characteristics of bolt are analyzed systematically, the mechanical performance is comprehensively tested, and the estimating formula of the anchorage force are obtained. On the base of the comparison of the anchorage performance to resin bolts, the applicable conditions of the new type bolt are introduced.(2) Aimed at the stress characteristic of bolt support, the simplified mechanical model is established to analyze the stress and deformation of the anchored surrounding rock. The analytical solution of stress field of the anchored surrounding rock is gained firstly by means of the Boussinesq solution and Mindlin solution in classical elastic theory. The distribution law of the axial, radial and annular stress of the anchored surrounding rock is presented and the difference of stress distribution characteristic between the mechanical reusable end-anchored bolt and resin bolts with different anchored length are compared, which revealed the mechanical mechanism that the anchorage performance of the end-anchored bolt is superior to the resin bolt.(3) Numerical simulation is adopted to study systematically the distribution characteristic of the axial stress along bolt, the radial stress and equivalent stress vertical to bolt in anchored surrounding rock. With the help of strength theory, the influencing law of bolt support with different anchored length on the strength of surrounding rock. The study results indicated that: the strengthening effect of the mechanical reusable end-anchored bolt on the anchored surrounding rock is relatively high, and the strengthening acting range is relatively large.(4) The action effect of bolt support on the stability of roadway surrounding rock is study systematically to present the changing law of the stress, deformation and the plastic range with the anchored length and time. It can be found that: with the decreasing of the anchored length, the acting effect of the roadway surrounding rock similar to a pressure arch enhanced obviously; the roof-to-floor convergence and the side-to-side convergence of roadway decrease obviously; the capability of controlling rheological deformation of roadway strengthened.(5) According to the industrial field test, the support effect of the new type mechanical reusable end-anchored bolt are monitored systematically to verify the stability of surrounding rock supported by this new type bolt and the recoverability of bolt-rod. The monitoring results indicated that the new type mechanical reusable end-anchored bolt has a superior support performance compared to the same standard resin bolt.The study results can provide an important reference for the popularization and application of the new type mechanical reusable end-anchored bolt.更多还原