Abstract
To enhance the tenacity of buildings located along coasts such as tsunami evacuation buildings, the effectiveness of small-scale countermeasures that can be constructed by their administrators is investigated using a coupled fluid-structure-sediment interaction numerical model that can compute air-water two-phase flow. The investigation focuses on an impermeable tsunami-resistant wall at the seaward side of a building as the countermeasures, and generates a single leading long-period wave against the building with the wall. Numerical results show that the maximum tsunami force acting on the building can be overestimated by the resultant force of hydrostatic pressure calculated from the maximum inundation depth in front of it, suggesting that the numerical model is a useful tool to evaluate the maximum tsunami force using the vertical distribution of the wave pressure. Furthermore, when the wall is placed in the vicinity of the quay wall, a higher wall can effectively reduce the tsunami force acting on the building. In contrast, when the wall is placed in the vicinity of the building, it can be effective to shorten the wall in terms of the reduction in the tsunami force. In addition, the wall can delay the impingement of the tsunami and the onset of the maximum tsunami force for large tsunami height. From these results, it is demonstrated that the construction of the short wall near the building would be an effective countermeasure.
