Hollow grouted rock bolts are widely used in deep soft rock roadways. The density of grout has a significant influence on the anchorage quality. However, there is still a lack of effective methods to detect the grouting quality fast, accurately, and extensively. Based on the wave velocity and the law of stress wave transmission and reflection in the impedance mismatch, non-destructive experiment focused on the defect in the anchorage was conducted. The wavelet transform was used to analyze the test signals. The test results show that the free length of hollow grouted rock bolt could be accurately detected through the analysis of the stress wave signal by using the low-pass filter in the wavelet toolbox. The grouted length, defect length, and specific position of the anchorage section can be accurately detected through the analysis of the stress wave signal by using the high-pass filter in the wavelet toolbox. The research can provide experiment foundation for further study of grouting quality based on the non-destructive methods.

中文翻译：

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基于小波变换的空心注浆锚杆锚固缺陷无损检测

空心注浆锚杆广泛用于深部软岩巷道。灌浆密度对锚固质量有重要影响。但是，仍然缺乏有效的方法来快速，准确和广泛地检测灌浆质量。根据波速和应力波在阻抗失配中的透射和反射规律，针对锚固缺陷进行了无损试验。小波变换用于分析测试信号。测试结果表明，通过使用小波工具箱中的低通滤波器分析应力波信号，可以准确地检测出空心灌浆岩石锚杆的自由长度。灌浆长度，缺陷长度，通过使用小波工具箱中的高通滤波器分析应力波信号，可以准确地检测出锚固部分的特定位置。该研究可为基于非破坏性方法的灌浆质量进一步研究提供实验基础。