The Finite Difference Numerical Simulation of Elastic Wave Field of Anchoring Quality of Rock Bolts

Aim at the short of theoretical research existing in the anchoring quality of rock bolts, some studies about the elastic wave method are made. By using staggered grid finite difference method, we simulate the two dimension elastic wave under different conditions, such as the influence of surrounding rock, mortar condition and its defects. The results of simulation show that the changing of wave velocity of the surrounding rock and the mortar have no effect upon the arrival time of reflection wave from the bottom of the steel rebar, but they affect the reflection wave's frequency, and the mortar defects have some influence on the reflection wave's amplitude, the larger the mortar defects, the greater the reflection wave's amplitude. This paper also proposes a new way of mortar compactness computing in the anchoring quality of rock bolts.