预应力锚杆弹性波检测原理与应用

Principles and Application of Elastic Wave Method for Prestressed Bolt Testing

为了提高锚杆支护施工质量和降低垮巷冒顶事故发生率,综合振动理论和数值模拟技术研究了预应力锚杆弹性波检测技术,对于预应力锚杆的无损检测起到极大的推动作用.建立了与无预应力锚杆不同的预应力锚杆纵向振动力学模型,得出了影响锚杆时域波形、频谱曲线的几个主要锚固参数,采用ANSYS/LS-DYNA软件模拟了预应力锚杆在脉冲激励作用下的动态响应,分析了预应力锚杆动态响应与无预应力锚杆动态响应的异同,揭示了预应力、锚固段对锚杆动态响应的影响规律.现场测试结果表明,检测精度可以满足工程施工质量的需求.

In order to improve the bolt supporting quality and reduce the roof collapse ratio, the prestressed bolt elastic wave detecting technique was researched based on the vibration theory and numerical simulation, greatly promoting the non-destructive test of prestressed bolt anchor. The vertical vibration model of prestressed bolt anchor different from that of common bolt anchor was established and several important parameters affecting the time domain waveform and the frequency spectrum curve of bolt were obtained. The dynamic response of the prestressed bolt under the pulse stimulation was simulated by ANSYS/LS-DYNA software. On the basis of this, both the similarity and the differences in dynamic response between prestressed bolt and the common one were analyzed and the dynamic response rule of the bolt affected by the prestress and the anchor segment revealed. The results of in-situ test indicate that the test precision can meet the requirement for engineering construction quality.