ABSTRACT
Operation of ships and offshore structures in the Arctic region commonly needs to deal with sea ice. The properties of sea ice are associated with a high degree of uncertainty due to formation of the sea ice under very different conditions within different sea areas. Probabilistic models are frequently introduced in order to cope with this inherent variability of the sea ice and the associated ice loads. In some cases (thin ice, narrow structures and no snow) the thickness and the flexural strength of sea ice are crucial parameters in relation to the interaction between ice and sloping features. For design of Arctic structures, the ISO standard is widely employed by the offshore industry. The objective of the present paper is to investigate the uncertainty associated with the ice forces that are acting on sloping structures based on formulas given in the relevant ISO standard. The Nataf model is applied to study the effect of correlation between the sea ice thickness and its flexural strength. Moreover, varying slope angles both in upward and downward direction are considered in this analysis. Monte-Carlo simulation techniques are applied in order to assess the uncertainty associated with the global force due to the ice structure interaction both in the vertical and the horizontal direction.
