TUNNEL WORKING METHOD BY MAKING USE OF LATTICE GIRDER

摘要

An upper part of the soft ground is excavated and in the left and right side of the upper part, a beam(2) for preventing the settlement subsidence can prevent the subsidence of the ground since the beam is joined vertically toward the plural tunnels excavating direction, even though the heavy upper truss is installed therein. The twist of the pre-installed truss can be prevented and the increase of danger of the tunnel collapse or the damage is controlled.