Subway Tunnel method for widening and retaining wall tool

摘要

PROBLEM TO BE SOLVED: To achieve improvement in both safety and workability when constructing a widened section during excavation.SOLUTION: A method to construct a widened section while excavating an underground section executes: installation of an earth retaining wall and excavation of the object ground until an excavation depth reaches a planned widening place (a); excavation of an earth retained section which is prepared by earth retaining at the planned widening place using an earth retaining tool with one end thereof rotatably connected to an immobile point and the other end thereof pressed into the ground (b); and construction of a widening section through the earth retaining and excavation of the planned widening place by joining a new earth retaining tool to a back of the previous earth retaining tool (c).SELECTED DRAWING: Figure 6I