Large-Scale Hull Loading of Sea Ice, Lake Ice, and Ice in Tuktoyaktuk Harbour

Abstract

As part of an INSROP project, large-scale hull loading of first-year sea ice, two series of experiments were carried out to simulate ice loading on a ship’s hull. The first, Phase I, was a preliminary series on freshwater lake ice near Calgary, Alberta, and the second, Phase II, took place in Tuktoyaktuk Harbour in the Canadian Arctic also on essentially freshwater ice. Loading was generated by hydraulic actuators impressing a rigid indentor against an ice edge, and by using flatjacks. A finite element analysis of the test geometry was carried out to assess the deformation and stress distributions in the ice edge for cases with both undamaged and varying degrees of damage. The calculated and measured stiffness of the ice edge agreed for a realistic selection of elastic modulus of the parent ice and damaged ice. The field results did not show conclusively any influence of damage on the failure strength of the ice. A review of these results, and those from Resolute Bay sea ice obtained earlier, showed that the nature of the ice loading, depending on whether it was uniform pressure or uniform deformation, significantly affected the results. The failure stress for uniform pressure tests did not have any dependence on area or aspect ratio. The measured field results gave average ice pressures less than those recommended by the Arctic Pollution Prevention Regulations.