2023 Volume 79 Issue 18 Article ID: 23-18106
Medium-scale experiments on the collision applied by timber on a flat plate along with sea ice as a kind of tsunami debris were performed to investigate the applicability of the prediction method for sea ice collision force to other materials. At high collision speeds, sea ice caused brittle failures, but there was no fracture / separation of the timber, and the maximum collision forces by the timber were greater and their duration time were shorter than those by sea ice. The maximum collision forces of both sea ice and timber, which were normalized by the factors included in the prediction equation, were directly proportional to the collision speed, and they were roughly equal to each other. Therefore, it was presumed that the prediction equation could be used regardless of the physical properties and the failure mode. We also proposed a very simple method for estimating tsunami force and a tsunami fragility curve with tsunami debris such as sea ice floes and verified their validities from some trial calculations.