2D ANALYSIS METHOD FOR SLAB DISPLACEMENT RESTRAINT FOR THE SIDE WALL REMOVING IN THE WIDENING WORKS OF THE EXISTING CUT-AND-COVER TUNNELS

Abstract

 The widening works of the existing railway cut-and-cover tunnel are increasing as increasing the mutual direct operation. In this case, the length of side-wall removing of the tunnels tends to be longer. Therefore, there is a possibility that the tunnels designed on the assumption of the 2-dimensional behavior behave 3-dimensionally. In this paper, first, 3-dimensional step analysis based on finite element method is applied to the simulation of the widening works using hanging protection. Next, 2-dimensional analysis method based on beam-spring analysis is developed and considered in comparison with the field data.