海岸堤防背後の落堀をモデルにした津波減勢施設とその効果

Abstract

A facility for dissipating tsunami flood energy that modeled a pool dug by a tsunami flood has developed and evaluated its effect. Reducing tsunami flood energy is one of the important problem for a future huge tsunami counter- measure. The formation of pools at the toe of back slope of the coastal levees caused breaking a lot of coastal levees at the 2011 Great East Japan Earthquake tsunami. However, it is pointed out that the pools also played a roll of reducing flood disaster in backyard of coastal zone. The tsunami flood energy dissipator is settled in the foot of coastal levee. Two types of the tsunami flood energy dissipator that change its slope in the coast side were examined by the hydraulic model experiment. We evaluate the effect of reduction of tsunami flood velocity in three tsunami wave height. Results of the hydraulic experiment indicate that constructing the energy dissipator that has mild slope in the coast side can decrease almost 30% of the tsunami flood velocity.