| 摘要 |
PROBLEM TO BE SOLVED: To provide a construction method that eliminates the need for a process of face cutting of the arrival vertical shaft upon arrival of an open shield machine in an arrival vertical shaft, and eliminates the need for counter-excavation to the shield machine or removal of the upper part of the shield machine before entering a mine, and thereby reduces the processes, in an open shield method for sequentially burying a concrete caisson in columns.SOLUTION: In an open shield method, an arrival vertical shaft 17 is formed in a plane U-shape placing a steel sheet pile, and by opening the arrival direction of a shield machine 1, ground improvement 18 is provided inside this open port, the end of the shield machine 1 and a concrete caisson 4 is made to enter the inside of the arrival vertical shaft 17 by penetrating through the ground improvement 18, a pithead retaining wall is provided in the end of the portion of the ground improvement 18, the excavation in the arrival vertical shaft 17 is sequentially performed for an upper stage, a middle stage and a lower stage in a stepwise manner; and the shield machine 1 is removed.SELECTED DRAWING: Figure 3 |
