【作者】 张选利；

【导师】 王永岩；

【作者基本信息】 辽宁工程技术大学 ， 工程力学， 2010， 博士

【摘要】 柔性注压锚杆是一种结构新颖和锚固机理独特的新型锚杆,能主动适应围岩运动、便于检测锚杆内腔的压力并通过内腔压力的变化来监测矿压的变化、锚杆重量轻、容易实现锚杆的回收复用等优点。但其作用机制即作用规律和理论分析方法却不甚明确。因此,开展该课题的研究具有重要的理论意义及实用价值。作者通过理论分析、数值模拟计算、实验室模拟分析及现场实测分析等手段,对柔性注压锚杆这一新型锚杆的锚固特性进行研究和探讨,取得了一些有意义的研究成果和结论。将材料简化为线弹性体,应用弹性理论,给出了柔性注压锚杆杆体以及围岩的应力场和位移场的解析解。并在此基础上应用强度理论,假定锚杆盲端围岩具有足够的阻抗拉拔力以防锚杆被拉出锚孔,给出锚杆的最大许用拉拔荷载将由钢丝强度、杆体高分子材料强度和钢丝与杆体高分子材料之间的剪切强度三个方面来确定。忽略锚杆端面效应,将锚杆体与围岩的接触分析简化为平面应变的二维问题。建立二维接触问题有限元计算模型,研究了锚杆锚固系统主要参数对锚杆锚固效果的影响规律,给出柔性注压锚杆锚固系统的最优化状态:高强度钢丝应置于锚杆壁厚中间或稍偏外壁处;锚杆壁厚有一个合理的取值;合理选择钢丝根数和截面;一定的锚杆结构参数有其适用围岩材料范围等。从而为该新型锚杆的设计、制造以及应用提供依据。建立锚杆锚固系统三维有限元计算模型,对锚杆锚固段接触应力分布规律进行数值模拟。提出锚杆锚固段阻抗摩擦应力曲线,可以通过在锚固段锚头端设置一定的位移值这种二次加载方式而得到。并将锚杆锚固段纵向阻抗摩擦应力曲线命名为三个阶段:应力波浪段,应力平台段和应力速降段。通过地面试验和井下现场试验,对柔性注压锚杆的实验装置、试验方案、锚杆结构、锚杆抗拉拔载荷等进行了多方面的考核与验证,获得获得了满意的结果。将试验拉拔荷载同理论结果和数值计算结果进行分析比较,得出理论值与数值计算值两条线是近似平行的直线,这一定程度的相互认证了理论计算与数值计算的正确性;将摩擦系数看成是常数以及将材料简化为线弹性会引起试验值、理论值和数值计算值之间一定的结果偏差。对柔性注压锚杆群的锚固特性进行分析讨论,并以平顶巷道顶板柔性注压锚杆群锚固作用为例得出:锚杆群中每根锚杆横向影响范围都是局部的;群锚杆布控具有明显的纵向影响;顶板垂直位移对水平地应力的变化不够敏感,但对上覆层压应力的变化却非常敏感。更多还原

【Abstract】 Flexible pressurized anchor is a kind of new anchor which has new structure and unique anchoring mechanism. It can actively adapt for the motion of adjacent rock, facilitate the detection of anchor inner cavity pressure and monitor the change of mine pressure through the change of inner cavity pressure、the weight of anchor is light and it is easy to achieve recycling reuse of anchor. But its mechanism of action including the role of law and the methods of theoretical analysis is not clear and defined. Therefore, it has important theoretical significance and practical value to study the subject.The author has researched and explored anchorage properties of the new type of flexible pressurized anchor by the methods of theoretical analysis、numerical simulation、laboratory simulation analysis and field measurement analysis and has made some meaningful research results and conclusions.The material is simplified as linear elastic material body, applied elasticity theory, given the analytic solutions of stress field and displacement field for the flexible pressurized anchor rod and adjacent rock. And applied strength theory on this basis, assumed that blind-side rock bolt has sufficient resistant pullout force in case that the anchor bolt can be pulled out of anchor bolt hole, Given the maximum allowable pullout load of anchor which is determined by the strength of steel wire、the strength of rod polymer material and the interfacial shear strength between steel wire and rod polymer material.Ignore effects of Interfacial anchor,simplify analysis of contact anchor bolt body with rock to two-dimensional plane strain problem. Establish finite element model for two-dimensional contact problem, study the regulation of the main parameters of anchor bolt anchorage system for bolt anchoring effect. Give the optimum condition of anchorage system of Flexible pressurized anchor: there is a reasonable value of anchor wall; a reasonable choice of wire number and cross-section of the wire; some structural parameters of anchor bolt and its scope of application of rock material and so on. Thereby, provide the basis for the design, manufacture and application of the new anchor. Establish three-dimensional finite element model for anchor anchorage system, carry out numerical simulation for contact stress distribution of anchor anchorage section. Anti-friction stress curve of anchor anchorage section can be obtained by setting a certain displacement value on the head-end of anchor anchorage section, which is a secondary loading way. And the vertical curve is divided into three stages: Stress wave segment, stress plateau segment and stress downhill section.Assess and verify many aspects of flexible pressurized anchor through ground test and under shaft field test, such as experimental installation、testing program、anchor structure and anti-pullout anchor load and so on, and obtain satisfactory results. Compare the values of experimental pullout load with theoretical results and numerical analysis and come to the result that the line of theoretical values and line of the values of numerical calculation are two approximate parallel straight lines. And the result certifies the accuracy of theoretical calculation and numerical calculation in a certain degree; that coefficient of friction is considered as a constant and simplified as linear elastic material lead to a certain deviation caused by experimental values, theoretical and numerical values.The analysis and discussion on the characteristics of flexible pressurized anchor group and the anchoring effect of the flexible pressurized anchor group of flat tunnel roof show that : the horizontal effect of each anchor of anchor bolt groups is partial; the layout of anchor group has a obvious vertical effect ;the change of the vertical displacement of roof to the level stress is not enough sensitive while to the change in stress of the overlying strata is very sensitive.更多还原