Abstract
After 2011's tsunami , there are a few physical experiments on the stability verification of breakwaters under overflow. These results indicated that the unstability of caisson increases as the difference of water level between front side and rear side increases. The estimation formula for the lateral force under the overflow was also submitted under the limitation number of experiments. The applicability of this equation is not clear. So, in this paper, the applicability of empirical formula is verified by using the numerical simulations. The results indicated that the empirical formula could estimate the stability as the safety side. Through the numerical tests with various shape of the cassions, the device such as parapet or something make the lateral force decreasing because of increasing the vertical force at the crown or increasing the supporting force at the rear side. The economical shape of caissons can be designed against the overflow.
