Abstract
The properties of high frequency longitudinal guided wave propagating in a free bolt and grouted rock bolts were studied by experimental methods. Guided waves with frequencies 1~3 MHz were used to inspect rock bolts, and the optimal excitation wave frequencies were obtained. Under the optimal frequencies, the amplitude of bolt end reflected waves has a maximum value, and the propagation velocity of guided waves in the rock bolts reaches a maximum value too. Furthermore, guided wave velocity values in a free bolt are close to that of the embedded section the rock bolt. As a result, the position of flaws on the bolt can be determined by the velocity of the high frequency guided wave in a free bolt and the reflected waves of the flaws.
| Original language | English |
|---|---|
| Pages (from-to) | 121-124 |
| Number of pages | 4 |
| Journal | Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology |
| Volume | 31 |
| Issue number | SUPPL.1 |
| Publication status | Published - Oct 2011 |
Keywords
- Free rock bolt
- Grouted rock bolt
- High frequency longitudinal guided wave
- Optimal excitation frequency