煤矿巷道锚杆（索）预应力锚固主动约束机理及设计方法研究

Prestressed anchorage based on resin anchor bolt or anchor cable is asignificant technology to resolve support problems of coal mine roadways in our country. In view of the problems occurring in prestressed anchor bolt or cable in coal mine roadways with simple and complex engineering conditions, this paper takes the bolt or cable support problem in roadway with typical engineering conditions as its research subject, and considers some key factors, such as, roadway surrounding rock conditions, bolt or anchor cable anchorage patterns, anchorage performances, etc. Then, starting from the evolution law of pull-out force and progressive failures of the anchoring bond under the pull-out force, the present paper investigated the constitutive relations between pre-tightening force and pull-outforce of the bolt and anchor cable,studied the reasonable value of pre-tightening force under active constraint, put forward the active constraint mechanism of prestressed anchoraged, and analysed the basic laws of the generation, evolution characteristic of prestressed anchorage and bearing capacity of prestressed anchorage body under the condition of rotatively-anchoring bolt and tensionally-anchoring cable. Based on the thought of prestressed anchorage, this paper further discussed the synergistic effect of the prestressed anchorage between the bolt and cable, and proposed a new method for designing bolt and anchor cable support, providing beneficial guidance for supporting designs in coal mine roadways. Meanwhile, research achievements, presenting in this paper, are of great instructive significance for the selection ofmaterials of bolt andanchor cable body, the development of anchor agent and the design of the prestressed force of the bolt andanchor cable.

基于树脂锚固锚杆（索）的预应力锚固技术是解决我国煤矿巷道支护问题的重要途径，本研究针对煤矿巷道简单和复杂条件下锚杆（索）支护的预应力锚固问题，以典型围岩条件下巷道锚杆（索）支护的工程问题为对象，考虑巷道围岩条件、锚杆（索）锚固方式、锚固性能等关键因素，从锚杆（索）拉拔力的演化规律和拉拔作用下锚杆（索）粘结体渐近破坏特征研究入手，探讨锚杆（索）预紧力与拉拔力的本质关系；研究主动约束条件下锚杆（索）合理的预紧力值，提出实现预应力锚固的主动约束机理；分析锚杆旋转加锚和锚索张拉加锚条件下，锚固围岩内预应力演化的基本特征和预应力锚固体的承载性能；基于预应力锚固的思想，进一步探讨锚杆-锚索预应力锚固的协同作用，提出煤矿巷道锚杆（索）支护设计的新方法，为煤矿巷道合理的支护设计提供指导。同时，这一研究成果对锚杆（索）杆体材料、锚固剂发展、锚杆（索）的预应力设计具有重要的指导意义。

树脂锚固锚杆（索）的预应力锚固技术是解决我国煤矿巷道支护问题的重要途径，本研究针对煤矿巷道不同条件下锚杆（索）支护的预应力锚固问题，以典型围岩条件下巷道锚杆（索）支护的工程问题为对象，研究了破碎巷道预应力锚杆控裂机制，探讨了预应力加锚和无锚条件下破碎巷道应力场和裂隙场的变化特征，揭示了预应力锚杆抑制破碎巷道的裂隙扩展规律；构建了“三体两面”非全长锚固单元体模型，揭示了煤矿巷道锚杆约束机理及破坏特征规律，实验研究了锚固段载荷的变化特征，基于细观数值模拟方法，明确了锚杆滑移脱粘破坏模式的影响规律，提出了非全长锚固单元体锚杆滑移脱粘失效准则；建立了完全弹性阶段煤岩-锚固剂界面力学模型，明确了锚杆锚固力学效应和承载主控因素，推导了锚杆弹性和塑性阶段剪应力和轴力的分布规律方程和临界锚固长度计算方程；基于预应力锚固思想，提出了围岩可锚性和锚杆材质最优化的支护原则，设计了锚杆锚固力、预紧力和锚固长度的具体优化方法，进行了具体工程案例分析，验证了研究成果的可靠性。所得研究成果为煤矿巷道合理的支护设计提供指导。同时，研究内容和部分成果对锚杆（索）杆体材料、锚固剂发展、锚杆（索）的预应力设计具有重要的指导意义。