UNDERWATER EXCAVATING METHOD USING UNDERWATER SAND PUMP, AND UNDERWATER SAND PUMP

摘要

PURPOSE:To enable the ground or the like of hard earth to be excavated and enable the ground of the lower end section of a covering body to be uniformly excavated by positioning external once among a plurality of jet-water jetting nozzles, near the lower end section of the covering body, at the same time as a plurality of the jet-water jetting nozzles are arranged around a suction section. CONSTITUTION:On the peripheral section of a partition panel 6, namely, around the lower section of a casing 1, for example, ring-shaped feed water pipes 8a, 8b are doubly arranged at an interval in the radial direction. On the lower surfaces of the respective ring-shaped feed water pipes 8a, 8b, holes are arranged at intervals, and on a section having the holes the upper end of a rectangular pipe 8c is firmly fitted by welding or the like, and at the lower end section of the rectangular pipe 8c, jet- water jetting nozzles 10 are removably fixed. Besides, on screw sections 8d set at the lower end section of the rectangular pipe 8c, the screw sections 10a of the jetwater jetting nozzles 10 are spirally fitted to be fixed. Then, the positions of the ring-shaped feed water pipes 8a, 8b with the fitted jet-water jetting nozzles 10 are contrived to be freely changed via a crawler crane.