The underground tunnel anchoring mechanism is analyzed by using the numerical simulation method. In the case study

considering the existence and nonexistence of the loose loop

anchoring effect of the bolt on the wall rock mechanical properties is studied by analyzing the radial displacement and stress

the hoop displacement and stress of the wall rock and the axial stress of bolt. The radial displacement of the chamber surface in the loose loop model is larger than that in the no loose loop model. Under the action of the bolt

the place of peak value of the hoop stress is more approach the chamber wall. It indicated that one of the main functions is to control the displacement and bolt to enhance the stability of the wall rock through improving the stress state.