强力锚杆杆体尾部破断机理研究

针对煤矿井下部分强力锚杆尾部螺纹发生破断且无“径缩”问题，对锚杆杆体尾部螺纹段进行了受力分析，得到由于变径导致应力集中，球面自锁、球面回转中心不合理导致球面自锁使锚杆受力恶化；对杆体尾部进行了实验室试验，对破断杆尾进行了化验分析，试验了不同安装角度对锚杆受弯断裂的影响；采用有限元数值模拟方法，介绍分析了杆体尾部的力学状态及应力分布状况，得到最不利受力位置。在潞安漳村矿井下强烈动压巷道进行了工业性试验，针对部分锚杆出现破断问题，提出多项优化方案，减小有害受力对杆体的影响。

Failure mechanism study on tail of high strength bolt

Aiming at the problem that many high-strength rock bolts fail at the thread part without obvious decrease in diameter，analytical analysis on the stress status of the thread was performed.The results show that stress concentration due to the change in diameter and self-locking of the domed washer due to inappropriate rotation center of the washer worsen the mechanical status of rock bolts.Laboratory tests on fractured threads was carried out，chemical analyses were performed on the fractured threads，the effect of the varied installation angles on the bending fracturing of rock bolts was tested.The mechanical status and the stress distribution in the thread was carried out using finite element method，and the most unfavorable position of the rock bolts was identified. Field tests were performed in the roadways suffering severe dynamic mining-induced stresses in the Zhangcun Coal Mine，many optimization plans were proposed to solve the rock bolt fracturing issue and to relieve the effects of the unfavorable forces on the rod of rock bolts.