【摘要】 预紧力是影响锚固效能发挥的重要指标,为查明其关键作用与锚索张拉锁定的预紧机制,以ANSYS软件模拟方法,探讨了锚索预紧力高低对于锚固串群效应的影响机制,对比了张拉力与预紧力的区别与联系,通过构建拉簧串联模型,推导了锚索由张拉至锁定过程中各元件的受力变形,得出了预紧力形成的计算公式并给出了具体算例。研究表明:持压力越大、围岩越软、自由段长度越长、夹片跟进性能越好,预紧力越高,张拉力损失也越小。工程应用中应兼顾高预紧力的锁定形成及长期保持,综合采取超张拉、补偿张拉、优化自由段长度、匹配限位距离和改进限位方式、锚索注脂等措施,从而全面发挥锚索的支护性能。更多还原

【Abstract】 The pre-tightening force is a key index in bolting and anchoring engineering,because of its important influence on surrounding rock structures’ rigidity and anchorage group effect. The mechanism using ANSYS simulation and the cable’s pre-tightening course with mechanical analysis was investigated. According to its installation and pre-tighten process,a series drag springs model was put forward for mechanical analysis,which includes surrounding rock,cable,anchor cup,and anchor wedge. The difference and connection of installing tension load and pre-tightening force were analyzed in detail. Some formulas for pre-tightening force were deduced and demonstrated by a calculation example. The studies show that the bigger installing tension load,the softer rock,the longer free cable section and the better following performance of wedges,would lead to the bigger pre-tightening force and the smaller converting loss rate. In the engineering application,the super-tension,replenish-tension,optimal length of free section,improved restriction mode and lag resin bolt,could be applied to realize high pre-tightening force anchoring and better support efficiency.更多还原