This study examined the applicability to assess the damage of bridge from the flooding by fluid pressure evaluated using basic fluid formulas. The damage of road bridges on the Kuma River in 2020 was estimated. As the result, the damage pattern of each bridge could be generally evaluated . The propriety of this assessment method for outflow was confirmed. The level of the hydrodynamic forces acting on the bridges was estimated. The horizontal load coefficients calculated based on the hydrodynamic forces were 0.1 to 0.6. Therefore, it is considered that it is possible to assess the risk of outflow from bridges crossing rivers which are dug into the ground depending on the design age and the conducted seismic reinforcement.
