| 摘要 |
PROBLEM TO BE SOLVED: To provide an underground digging construction method being free from danger of a working face and sinking of the ground due to the replacement of advancing pipes, shortening a construction term, and realizing safe and sani tary construction. SOLUTION: Cylindrical solid materials made of a foaming styrol member are compressed in an advancing pipe 1 and are pushed in one after another until they reach a working face 5. This pushing-in operation is done by a propulsion device 6 of the propulsion pipe. The advancing pipe 1 is pulled out while pressing cylindrical solid materials 3. A release part 7 of the cylindrical solid material 3 coming out of the advancing pipe 1 is inflated and restored due to its restoration property, knocks against a pit wall, and presses the pit wall to prevent the collapse in a pit and expand a collapse prevention scope in accordance with pulling out of the advancing pipe 1. |
