Study on the effect of tunnel face stabilization using the distinct element method

This study aims to investigate the effect of face stabilization using a three-dimensional distinct element program for granular media. First, tri-axial compression tests were simulated to study the correlations between the properties analytically determined, including the contact stiffness and the bond strength of particles forming ground, and the properties actually obtained through tests. Furthermore, collapses at tunnel faces were simulated to study the mechanism of collapses that might occur around the face. The authors compared different face-stabilizing methods to verify the effect of the long face bolting. In addition, this paper discusses how face behavior varies depending on the spacing of long face bolts.