PAPERS |
Shinji KONISHI, Tatsuya NISHIYAMA
This paper describes the influence of three-dimensional effect on tunnel face stability. To investigate the effect, model experiments and simulation analyses were performed by the three-dimensional rigid plastic finite element method (3D-RPFEM). As a result, the followings were made clear concerning the state of the ground at face collapse. First, the three-dimensional stress distribution in the ground in front of the face can be made clear by the 3D-RPFEM analysis. Second, the vertical earth pressure decreases in the sliding zone and increases in the range surrounding the sliding zone at the crown level. Third, the clay layer in the sandy ground transmits loosening in a lower sandy layer to an upper sandy layer widely and weakly.
Copyright (c) 2002 Railway Technical Research Institute