The Influence of Water Content on the Thermoerosion Rate of Frozen Sand in Moving Water

The study of the thermal and mechanical erosion of frozen sediments in moving water within regions of continuous permafrost has occurred since the 1970's as a result of development in Alaska, Canada and Russia. While the influence of water temperature has been published in several technical papers, the influence of the water content of frozen sediments is undocumented. It was the hypothesis of this thesis that the water content was an important variable. Laboratory thermoerosion experiments were conducted using a high sheer stress flume for ice and sand with four different frozen water contents at two water velocities and three water temperatures. The subaquesous thermoerosion rates of 42 frozen samples were measured and varied from 0.025 mm/s to 0.45 mm/s. An equation was developed which estimates the thermoerosion rate dependent on the frozen sample water content and the water temperature and velocity. The results demonstrate that in order to effectively estimate the thermoerosion rate of frozen sand in moving water, the water content of the frozen sample must be accounted for.