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在实验室制作了完整锚杆和不同缺陷锚杆系统模型,利用小锤锤击和超声波两种手段进行了室内模型实验,得到了相应的测试结果。通过分析认为,完整锚杆和有不同缺陷锚杆的时域响应曲线和频谱曲线有较明显的差别。用小锤激发的方式,由于各种因素的影响,杆底及缺陷反射信号不明显;而用超声波激发的方式,信号的噪声较小,杆底反射信号较明显,但缺陷处反射波较难判断。完整锚杆反射波的能量集中在较窄的频带上,而缺陷锚杆分布在较宽的频带上。
In the laboratory, a complete bolt and different defect bolt system model were produced. The indoor model experiment was carried out by means of hammer hammering and ultrasonic wave, and the corresponding test results were obtained. According to the analysis, there is a clear difference between the time-domain response curve and the frequency spectrum curve of a complete anchor rod and a bolt with different defects. Due to the influence of various factors, the reflected signal of the sole and the defect is not obvious. However, with the method of ultrasonic excitation, the noise of the signal is small and the reflection signal of the rod bottom is obvious. However, the reflected wave at the defect is hard to beat judgment. The energy of the complete anchor reflected wave is concentrated in a narrower frequency band while the defect anchor rod is distributed over a wider frequency band.