Abstract
We started the seawall construction of the Tomari nuclear power station unit 3 from March in 2001. Before the construction, since it was necessary to reduce costs of the seawall, we tackled development of new type seawall. In this development, we tested several forms of seawall and investigated functions and improved weak points of seawall by hydraulic model tests, and finally developed the low crest seawall that fitted for field condition and made it possible to reduce costs. It was found by hydraulic model test using multi-directional random waves that wave overtopping quantity was within the permissible range inall place of the seawall, and the blocks were unstable though the wave pressure was low at the concave section, so we put the high specific gravity blocks to improve stability and miniaturize the caissons to reduce costs at the concave section. The seawall was nearly completed, we started the field survey to verify wave pressure characteristics.
