| 摘要 |
PURPOSE:To easily settle a caisson into water by a method in which a hydroulic excavator of an inverted umbrella type is set below the bottom plate of the caisson, and mud water excavated by the excavator is collected in preceding pits and discharged by a sand pump. CONSTITUTION:A hole 6 in the bottom plate of a caisson A is led to the hole 5 of a hydraulic excavator 1 of an inverted umbrella type, and an excavator 1 is set below the caisson A. The ground is excavated in an inverted square- conical form by jetting water from the nozzle 3 of the water pipe 4 of the excavator 1, and the excavated soil is collected in the preceding pit 7 through pits 5 and 6. The soil with water is sucked up through a sand pump 8 inserted into the pit 7 and discharged separately from water, and the water so separated is returned into the excavating section of the caisson A. The caisson A is further settled to a given depth, and the excavator 1 and the pump 8 are pulled up. Reinforced concrete is then placed into the space of an inverted square- conical form and the pit 7. |
