EXECUTION OF CAISSON

PURPOSE:To facilitate construction by installing a caisson in which iron reinforcements are projected from a wall surface at the slab position under water onto the bottom of water and throwing the inside filling sands into the caisson and binding the previously assembled iron reinforcements onto the iron reinforcements and laying slab concrete. CONSTITUTION:A caisson is prepared in the state where iron reinforcements 13 are projected from a side wall and a partitioning wall, and transported to an installation position. Then, water is poured into the caisson, and said caisson is installed at a prescribed position on a foundation cobble stone levelling position on the bottom of water. Then, the inside filling sands S are thrown into the caisson, and the inside filing sands S are thrown up to the part where the iron reinforcements 13 are projected on a retarding part 3 side having slits 2. Then, a previously assembled iron reinforcement 15 is setting-bound onto the iron reinforcement 13. Further, in the state where water is left in the retarding part 3, a slab is prepared by laying slab concrete by using the special under water concrete.