A PROPOSAL OF THE SIMPLIFIED MODEL TO EVALUATE THE EFFECT OF LONG FACE BOLTING

Abstract

The stability of advanced ground core is essential to excavate the tunnel by NATM safely and stably. Therefore, long face bolting has been widely used to reinforce and support the advanced ground core especially in soft rock. In this study, a simple axi-symmetric FEM model was developed to evaluate the effect of the face bolting quantitatively. The calculated results such as tunnel convergence and surface subsidence were compared with the results of in-situ measurement. It was found that the calculated results reasonably coincided with the measured results indicating an enough potential and effectiveness of the proposed model.