Abstract:Based on the anchorage mechanism of bolts,a model for the anchorage system is established. An embedded bolt can be regarded as a waveguide according to the propagation properties of guided waves. The frequency equations of axisymmetrical longitudinal guided waves for the embedded bolts are deduced;and the dispersion curves are plotted. According to the optimal simulation results of guided waves at high and low frequencies,the reflection from the upper interface of anchorage segment can be detected at a frequency of 75 kHz;and the effective bonding length of the embedded bolts can be further figured out according to the reflection time and wave velocity. The end reflection of the bolt can be identified at 2 MHz;and the attenuation coefficient for bolts can be obtained according to the relationship between incident and reflected waves amplititudes,by which the archorage quality of the embedded bolts can be evaluated.