PURPOSE: To reduce the weight of a structure by controlling water pressure between a bottom slab of a structure body constructed on the foundation side bottom slab and a bottom slab to make it possible to control frictional force between the bottom slabs, and making it possible to combine the body with the bottom slab and separate.
CONSTITUTION: After a structure body 1 is constructed on the foundation side bottom slab 3, water is poured in a dry dock to make the structure body float. Water pressure between a body bottom slab 1b and a bottom slab 3 is kept in smaller than external water pressure by a constant water level device mounted to a water collecting pipe 10e to combine the body 1 with the bottom slab 3. After the body 1 combined with the bottom slab 3 is towed to a construction site, a water ballast is filled with water to install the body directly on the sea-bottom 2 together with bottom slab 3. In addition, when the body 1 is moved again, the water pressure between the bottom slabs 1b and 3 is kept in smaller than the external water pressure to combine the bottom slab 3 with the body 1, and after the ballast is removed, the body is floated again to tow.
KUSANO NAOMIKI
OTOFUJI KANJI
