A Study of effective installation patterns of face bolts using 3D-FDM analysis

터널 안정화를 위한 페이스볼트의 효율적 배치에 관한 수치해석적 연구

  • Published : 2006.06.30


For application of NATM, the self-supporting until installation of the supporting system must be satisfied. However, the face of a tunnel are always unsupported and therefore it is fairly vulnerable to tunnel collapses. Face blots are well known and widely used to prevent the deformation of the tunnel face and its circumference, which are installed horizontally toward the tunnel axis generally. To maximize the supporting effect of face bolts, this study has analysed the effective design patterns of face bolts by changing their installation angles. As the conclusion, it has been found that the axial displacement of the face increases slightly by installing the outermost bolts upward from the axis but surface settlement at 2.5D behind the face decreases up to 18%.