Author(s): P. A. Spencer; D. M. Masterson
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Keywords: No Keywords
Abstract: A Monte-Carlo simulator has been constructed to calculate 100 Year ice loads on multilegged offshore drilling structures. The model considered the interaction between a first year pressure ridge and the structure. The ridge was represented as a consolidated layer, a partially consolidated layer and rubble in the keel of the ridge. The model allowed for ice failure at the ice structure interface and behind the feature, usually a ridge fragment. The model also included a first-year level ice pressure formulation based on considerations of limited driving force. The minimum of the load at the structure interface and behind the ridge was taken as the load for that event. On a year-by-year basis the maximum load event was retained and generally 1000 years of simulation were run from which 100-year load levels were obtained. Statistical data was calibrated for the offshore Sakhalin region using input from upward looking sonar, on ice measurements programs, aerial survey and international data on-ice strengths. Development effort was expended to allow for arbitrary waterline shapes and numbers of legs or structural elements in the model. The model has been used for 1,3 and 4legged structures as well as octagon shaped caissons where each side is treated as a separate element. The general features of the model along with the major functional dependence of the ice loads will be given.
Year: 2002