Medium-scale model experiments on soil deformation and stress within seabed during ice scour event

Abstract

Ice-Scour Event is a phenomenon that occurs when deformed ice such as an ice ridge comes into contact with seabed. Ice-Scour has been reported to cause damage to communication cables and water intake pipelines. As well as the estimation of the scour depth or burial depth of structures, it will be also important to consider a sub-scour deformation, which means stress transmission or soil deformation within the seabed below sea ice. In addition to our previous model tests related to the sub-scour deformation under the small scale condition (Kioka et al., 2004), we made a medium-scale model test. We confirmed that the stress within the seabed during ice-scouring did not depend on a drift speed of a model ice, and that the restriction due to attack angle was large. We also found that stress and reaction force greatly depend on relative density of soil. From the small-and medium scale model test results, we clarified the scale effects/similarities concerning reaction forces and stress distributions withinthe seabed.