If Tokai-Tonankai-Nankai earthquake occurs, the associated tsunami will strike Osaka and ascend Yodo river in Japan. When tsunami runs up a river, bridges on the river can obstruct the flow. This study aims to estimate the effects of bridges on tsunami runup in Yodo river by applying a three dimensional numerical model to simulate the water behavior. As a result, it is found that the effect of bridges causes water level rise and associated velocity decrease of the tsunami in the bridge vicinity. In addition, this study gives the result that the energy of tsunami decays at the upper reaches of bridges because of the obstruction to the flow. In the case where the tsunami water level is five meters high, tsunami does not overflow the river banks but may overflow around bridges and flood the landside area.
展开▼
