煤矿螺纹钢锚杆螺帽–盖板连接松脱扭矩合理性研究

Research on the Rationality of Loosening Torque for Nut-Plate Connection of Threaded Steel Bolts in Coal Mines

摘要: 针对煤矿井下螺纹钢锚杆安装过程中螺帽–盖板连接件松脱困难、施工设备负荷偏大、单根锚杆安装时间延长以及锚固质量波动等问题，在现场调查基础上，采用机理分析、分组试验、统计评价框架和文献对比相结合的方法，对螺帽–盖板连接松脱扭矩的合理取值进行了研究。结果表明，松脱扭矩的本质是施工启动力矩，其主要作用是保证盖板在安装初期顺利松脱，使锚杆进入连续旋转搅拌状态，而不是通过提高该数值直接提高锚固性能。据此设计实验，A、B、C、D四组平均锚固力分别为261.1、254.3、258.7和218.1 kN。当松脱扭矩处于60~120 N·m时，盖板松脱顺畅，树脂搅拌状态较稳定，锚固力满足现场支护要求；当松脱扭矩超过120 N·m后，钻机启动负荷和操作阻力明显增加；当扭矩达到180~200 N·m时，常规锚杆钻机难以稳定开启盖板，部分试件出现搅拌不连续和混合不均现象，锚固力明显降低。结合螺纹连接扭矩控制、树脂锚固剂搅拌及锚杆安装质量研究，松脱扭矩应与施工设备额定能力、锚固剂搅拌工艺和现场可操作性协同确定，避免将其简单理解为“越大越好”。研究结果可为煤矿螺纹钢锚杆产品设计、现场施工和质量控制提供参考。

Abstract: In view of the practical problems of difficult loosening of the nut-plate connection, excessive equipment load, prolonged installation time, and fluctuation of anchoring quality during the installation of threaded steel bolts in coal mines, the rational range of the loosening torque was studied by means of mechanism analysis, grouped tests, statistical evaluation framework, and literature comparison based on field investigations. The results show that the loosening torque is essentially a construction starting torque. Its main role is to ensure that the cover plate can be released smoothly at the initial installation stage and that the bolt can enter a continuous rotating and mixing state, rather than directly improving anchoring performance by increasing the torque value. Experiments were designed accordingly: the average anchoring forces of groups A, B, C, and D were 261.1, 254.3, 258.7, and 218.1 kN, respectively. When the loosening torque was controlled within 60~120 N·m, the plate could be released smoothly, the resin mixing process was relatively stable, and the anchoring force met the field support requirements. When the torque exceeded 120 N·m, the starting load and operating resistance of the bolting machine increased significantly. When the torque reached 180~200 N·m, the conventional bolting machine could hardly release the plate stably, and discontinuous mixing and non-uniform resin distribution occurred in some specimens, leading to a significant decrease in anchoring force. Combined with studies on torque control of threaded connections, resin grout mixing and bolt installation quality, the loosening torque should be determined in coordination with equipment capacity, resin mixing requirements, and field operability, rather than being simplistically interpreted as “the larger, the better”. The results provide reference for product design, on-site construction, and quality control of threaded steel bolts in coal mines.