| "In order to clarify the effect of rock bolts and the influence of the timing of installing rock bolts in sandy ground, a series of tunneling model tests, simulated by a trapdoor apparatus, are carried out. The results show that rock bolts with a certain level of length have the effect of reducing the load on the trapdoor and rock bolts installed after the occurrence of the loosened area have the similar effect as the rock bolts installed before the occurrence of the loosened area when the overburden is large. In order to verify the experimental results, a numerical simulation by the FDM analysis is conducted using the cable elements. By calculating the settlement of the ground and load on the trapdoor, it is confirmed that the analytical results reasonably explain the experimental ones." |
