Development of Precast Form Caisson

Abstract

This study describes the design and benefits of a new type of caisson called the "precast form caisson". Many recently developed caisson construction methods use full-precast plates, whose joints are poor in durability and load bearing capacity. Design and construction methods that c0mpensate for these weaknesses by using full-precast members are very c0mplicated, making them inferior in cost and effectiveness. The authors overcame those drawbacks by using a precast form concrete caisson that has half-precast members and a reinforced concrete c0mposite structure. The caisson is made of H-steel and c0mprises a high-durability precast form and an RC precast form, which are filled with super-plasticized concrete. In July 1999, we produced a precast form caisson measuring 14 m long, 12 m wide and 11 m high in T0mak0mai Port, to verify the method's effectiveness and econ0mic feasibility.key Words : precast form caisson, construction method, highly durable permanent formwork, reiforced concrete permanent formwork, embossed H-section steel