矿用锚杆动态力学性能试验研究

Experiment on dynamic mechanical properties of mine bolts

为研究冲击载荷作用下矿用锚杆的动态力学性能,选取蒙陕矿区冲击地压巷道常用的锚杆材料,利用AW-1500微机控制电液伺服试验机和落锤冲击试验机分别测试了锚杆的静、动载力学性能,获取了锚杆载荷与位移曲线、冲击力时程曲线、位移时程曲线等数据。研究发现:锚杆冲击力时程曲线分为急剧增加、平稳和衰减三个阶段。随着冲击次数或冲击能量的增加,锚杆的冲击力峰值逐步增加,锚杆冲击力稳定在200~300 kN之间,当锚杆达到冲击破断时,冲击力峰值位于250~300 kN之间。冲击载荷作用下锚杆杆体破断位置颈缩不明显,表现出明显的脆断特征,动态破断载荷略大于其静载破断载荷,而延伸率大幅度降低,动载下的断后延伸率为10%左右。该研究结果可为冲击地压巷道锚杆支护设计和材料选取提供一定的试验依据。

To study the dynamic mechanical properties of mining bolts under impact load,we employed the common bolt materials for rock burst roadways as examples from Inner Mongolia and Shaanxi mining areas.The static and dynamic mechanical properties of bolts were tested by means of AW-1500 microcomputer controlled electro-hydraulic servo testing machine and drop hammer impact testing machine,which provided the bolt load displacement curve,impact force time history curve,displacement time history curve and other data.It was found that the time history curve of bolt impact force can be divided into three stages:sharp increase stage,stable stage and attenuation stage.With the increase of impact times or impact energy,the peak impact force of the bolt increases gradually,and the impact force of the bolt varies 200~300 kN.When the bolt reaches the impact breaking point,the peak impact force is between 250~300 kN.Under the impact load,the necking of the breaking position of the anchor rod is not significant,obviously showing brittle fracture characteristics.The dynamic breaking load is slightly bigger than its static breaking load,while the elongation is greatly reduced,and that after fracture under dynamic load is about 10%.The research results can provide some experimental basis of design and material selection for rock bolts support in rock burst roadways.