Author(s): Denise Sudom; Garry Timco
Linked Author(s):
Keywords: No keywords
Abstract: The Steel Drilling Caisson (SDC) was used by Devon Canada to drill an exploratory well at the Paktoa C-60 site in the Beaufort Sea during the winter of 2005-06. Three major storms were experienced at the site during the deployment; this paper focuses on the final storm event which occurred February 22 to 23,2006. At that time, the ice surrounding the SDC was landfast and 1 m thick. The ice near the SDC buckled overnight, with total horizontal ice movement of approximately 1 to 1.15 m. In-place inclinometer data showed that late on February 22, a maximum deflection of 35.5 mm occurred in the soil 0.55 m below the foundation skirts of the SDC. This paper examines the available data and uses four different approaches to estimate the ice force on the SDC during this loading event. From this analysis, predicted results from the three most reliable approaches range from approximately 55 to 89 MN. Global pressures are in the range of 0.65 to 1.04 MN/m2, over an effective structure width of 85 m. The geotechnical sensors provide an interesting approach for inferring the loads on the structure and their response predictions are in general agreement with analytical and empirical-based approaches. Suggestions are made on questions that should be addressed to make this approach more reliable for load predictions.
Year: 2008