Reduction of tsunami force acting on large-sized tsunami shelter

After the Tohoku earthquake tsunami in Japan, many evacuating options from a huge tsunami have been proposed in recent years. To design these options at a devastated area, we should consider characteristics of local community, industry and population, especially, barrier-free for children and senior citizens. In this paper, we have proposed and developed a large-sized tsunami shelter that is capable of accommodating at least two hundred people or more to evacuate from a run-up tsunami. The developed tsunami shelter in this research has a curved surface shape to reduce the tsunami force. The idea for the shape has been created by a fluid and aero dynamics design on a ship and a super express train technology. The optimization for the shape was computed using Smoothed Particle Hydrodynamics, SPH method. To investigate fluid force on the optimized tsunami shelter, impact pressure and averaged force caused by a run-up tsunami, we conducted some experiments and examined four kinds of tsunami shelters with different configuration. We found that the tsunami resistance of the desired shape can be greatly decreasing comparing with that of the basic shape, e.g. a rectangular shape. The proposed tsunami shelter could be one of useful options for evacuating from a huge tsunami attacking near coastal area.