Design of bridges with submerged floating foundations

Considered in this paper is a floating bridge with submerged floating foundations. The buoyancy force of the submerged floating foundations is designed to be more than the total loads of the bridge including live loads so that the net buoyancy force is supported by a tension of anchor cables. Because of the tensioning of the anchor cables, the submerged floating foundations are supported very stiff and their motion becomes very small. As a first step of research works on this type of floating bridges, discussions are made on the design of the submerged floating foundations subjected to the wave forces. The wave forces on the submerged floating foundations are evaluated by using “source distribution method,” and the results are verified by the experiments using an 1:100 scale model. In the wave force evaluations, some geometrical shapes are compared. Preliminary design of the bridge with submerged floating foundations has also been made.