Analysis on the anchoring effect of the point anchoring rockbolt and the full length rockbolt

A modified discontinuous deformation analysis (DDA) algorithm was proposed to study the deformation mechanism of rockbolt nearby the fracture surface and the interaction between the rockbolt and the fracture surface. In the modified method, it is assumed that the rockbolt has no deformation in rock mass and its restriction effect on the fracture surface can only be considered. A normal and tangential spring is applied to the fracture surface separately to simulate the full length rockbolt. A tunnel was reinforced by using the full length rockbolt and the point anchoring rockbolt respectively. The simulation results indicate that the modified discontinuous deformation analysis (DDA) method is effective for the reinforcement of tunnel. It is found that, in general, the anchoring effect of the full length rockbolt is better than that of the point anchoring rockbolt.