Ice loads on port structures in the Canadian Arctic

The growth of communities and economic activity in the Canadian Arctic is resulting in development of new port facilities. Some guidance for these developments has been gained from observations of ice behavior and measurements of local ice forces at Nanisivik. The ice conditions at the site are first-year fast ice during the winter preceded by a 2-to-3-week freeze-up period. During the melt and summer seasons the ice conditions can be described as mobile pack ice, with occasional glacial ice inclusions. The combination of fast ice, a 3-m tide and the steel construction of the wharf leads to the formation of a zone of disturbed ice between the wharf and the first-year ice, complicating the application of existing guidance documents to ice force predictions. Global ice forces based on application of ISO 19906:19 Arctic offshore structures standard yielded an annual global load of 22 MN on a 23-m diameter cell and 75 MN on the 100-m-wide Nanisivik wharf. Extrapolating from the annual mean line load measured on a 0.54-m width, a global load of 10 MN on the 23-m diameter cell was determined. Ice load measurements on hydropower dams provide direction in interpreting ice pressure data over various scales on structures. Observations of ice conditions and measurements of ice loads at Nanisivik, together with dam experience, provide a basis for guidance on predicting ice loading on port structures in the Arctic.