CONSTRUCTION METHOD AND EXECUTION DEVICE FOR FOUNDATION OF UNDERWATER STRUCTURE

PROBLEM TO BE SOLVED: To repeatedly use an execution device by making the execution device removable from a gabion sunk on the underwater ground. SOLUTION: An execution device 2 suspended from the crane of a work ship floating on the sea holds a reinforced cage 1 filled with a filler such as broken stones from above, air cylinders 20 are driven, and suspension hooks 19 are hooked on lifting slings 22 at the upper section of the reinforced cage 1. The reinforced cage 1 is suspended and lowered into the sea together with the execution device 2. The underwater ground is scoured to the planned depth by high-pressure air injection nozzles 10 and high-pressure water injection nozzles 9 at the lower end sections of the stanchions 4 of the execution device 2 while their injection angles are adjusted, then the air cylinders 20 are driven to remove the suspension hooks 19 from the lifting slings 22, and only the execution device 2 is lifted and recovered while the reinforced cage 1 is left on the underwater ground. The execution device 2 can be repeatedly used.