Abstract
The Okhotsk Sea coast of Hokkaido is covered with ice floes during winter. Aota et al. showed that the temperature in this region has been rising every winter, and in the last ten years the amount of sea ice has been decreasing. Therefore the period of coexistence of waves and ice floes has become more longer and it is very important problem to make clear the impact ice load acting on offshore, harbor and coastal structures which are constructed on Okhotsk Sea coast of Hokkaido. Saeki et al. and Takahashi et al. reported that the velocity of ice floes due to wind wave, overtopping over breakwater and tsunami was about 4-8m/s. In this paper, the authors clarified the impact ice load when ice sheets collide vertically with a circular cross-sectional structure.
