| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the excavation width and the excavation depth of the ground surface by constructing a shaft at an end part of a section from which an embedded pipe is withdrawn, cutting the embedded pipe in the circumferential direction with the prescribed intervals by a cutting device placed in the embedded pipe, excavating the ground surface, and excavating and withdrawing the embedded pipe. SOLUTION: In withdrawing an embedded pipe 11, a shaft 13 is constructed at an end part of a section from which the embedded pipe 11 is withdrawn, and the embedded pipe 11 is cut in the circumferential direction with the prescribed intervals by a cutting machine 17 placed in the embedded pipe 11 from the shaft 13. In the cutting machine 17, a torch 17b is provided on a truck 17a, and the torch 17b is rotatable in the circumferential direction of the embedded pipe 11. After the cutting work of the embedded pipe 11 is completed, a sheet pile for earth retaining is installed with the prescribed intervals on each side of the embedded pipe 11. The ground G between the pile sheets is excavated until the upper half part of the embedded pipe 11 is exposed. A hole is cut in each cut embedded pipe 11, and the cut embedded pipe 11 is hoisted one by one by a crane, etc., using the hole, excavated and withdrawn.</p> |
