College of Energy and Mining Engineering, Shandong University of Science and Technology
State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology
Ordos Haohua Hongqingliang Mining Co. Ltd

基于锚杆系统自由段横向振动特性的检测方法可实现对锚杆的大范围快速有效检测。为提升锚杆轴力检测精度,建立锚杆系统横向振动力学模型,测试了全尺寸锚杆系统轴向加载过程中的频率响应。结果表明:锚杆系统横向振动固有频率对转动刚度及锚杆自由段长度比较敏感;通过试验校准理论模型的转动刚度,所得理论预计轴力与试验结果的吻合度较好,频率阶次越低,轴力检测误差越小;轴力较低时,基频轴力检测的平均相对误差为5.8%,轴力较高时,平均相对误差仅为0.6%;当锚杆杆体进入塑性或界面脱粘滑移后,锚杆自由段长度变化较大,通过实时修正锚杆自由段长度,可实现锚杆系统损伤阶段的轴力检测,基频轴力检测的平均相对误差在4.1%以内。锚杆轴力的快速、无损检测方法对于支护系统及围岩稳定性评估具有重要意义。

The detection method based on the lateral vibration characteristics of the free segment of rock bolt system can quickly and effectively detect rock bolts on a large scale. To improve the accuracy of rock bolts axial force detection, this paper established a lateral vibration mechanical model for the rock bolt system and tested the frequency response of the full-scale rock bolt system during axial loading. The results indicate that the lateral vibration frequency of the rock bolt system is sensitive to the rotational stiffness and the free segment length of rock bolts. By calibrating the rotational stiffness of the theoretical model through experiments, the theoretical results obtained are in good agreement with the experimental results, and the lower the frequency order, the smaller the error in axial force detection. When the axial force is low, the average relative error of the fundamental frequency axial force detection is 5.8%, while when the axial force is high, the average relative error is only 0.6%. When the body of rock bolts enters plastic or interface debonding and sliding, the length of the free segment of the rock bolt changes significantly. By adjusting the length of the free segment of the rock bolt in real time, the axial force detection during the damage stage of the rock bolt system can be achieved, and the average relative error of the fundamental frequency axial force detection is within 4.1%. The rapid and non-destructive testing method of the rock bolt axial force is of great significance for the evaluation of support system and surrounding rock stability.

山东省自然科学基金项目(ZR2022ME158)