| 摘要 |
PURPOSE:To raise the settling efficiency of a caisson by a method in which while excavation is made by an expansion type excavator, a liquid-pressure cylinder is contractionally moved, and support beams and a caisson supported by the support beams are concurrently lowered. CONSTITUTION:The upper end of a caisson 3 is connected to the support beam 2 of an elevating supporter having a liquid-pressure cylinder 1 for vertically moving the support beam 2. An expansion type excavator 4 is hung down from the beam 2 for supporting. The excavating cutter 5 of the excavator 4 is expanded and opened and positioned below the lower end of the caisson 3, and the excavator 4 is operated for excavation. The cylinder 1 is contractionally moved and the beam 2, the caisson 3, and the excavator 4 are concurrently lowered. The settling efficiency of the caisson 3 can thus be raised by such a simplified process, and the degradation of the pit wall can be prevented. |
