关键词: 预紧力, 应力均布型锚杆, 静载, 动载, 力学响应, 数字散斑相关法(DIC), 锚杆破断, 落锤冲击, 霍普金森压杆(SHPB)

Abstract:

In order to solve the problem of bolt breaking and losing anchor due to the influence of strong mining stress in deep mining roadway, and effectively improve the pre-tightening force of the bolt, a stress uniform bolt with high pre-tightening force was designed. The theoretical analysis, static load drawing and drop hammer impact test, numerical calculation and DIC method were used to study the load-displacement distribution characteristics of the bolt in the process of static load drawing, and the stress concentration position of the bolt was obtained. The mechanical response characteristics of the bolt under dynamic load were studied by using Ansys numerical simulation of drop hammer impact test and SHPB impact test. The results show that the thread deformation of the ordinary bolt nut decreases exponentially along the axial direction away from the extrusion surface, and the strain is concentrated in the first three circles of the thread. The stress uniformly distributed bolt can achieve thread strain coordination, and the mechanical environment is good. The change of bolt axial force is divided into a rising zone, an oscillating zone and a stable zone. When the drop hammer impulse is the same, the stress uniform distribution bolt can reduce the impact force to 64% of the original, and reduce the amplitude frequency of bolt axial force. The stress uniform distribution bolt can reduce the amplitude and frequency of the stress wave waveform. The research results have been applied to deep roadways such as Zhuji mine, Paner mine and Dingji mine. The bolt has no broken anchor phenomenon, and the control effect of the roadway surrounding rock is good.

Key words: pre-tightening force, stress uniformly distributed anchor bolt, static load, movable load, mechanical response, digital image correlation (DIC), bolt broken, drop hammer impact, Hopkinson pressure bar (SHPB)