Author(s): Yung-Shih Wang
Linked Author(s):
Keywords: No Keywords
Abstract: A bottom-founded offshore structure in the deeper waters of the Beaufort Sea will encounter a variety of ice features during its service life, among which the consolidated, multiyear pressure ridges will likely generate the most severe ice loads. To minimize the ice load, the preferred structural configuration in the ice contact zone is a sloping surface to fail the ice in flexure. Therefore, accurate prediction of ridge loads on a cone is of major significance in the design of such structures. Ridge loads on cones have been previously investigated in the literature. Analytical procedures have been developed for load predictions based on an elastic description of the ridge with a brittle failure criterion. However, when compared with model test results, the elasticity method often underestimates the ridge loads. This paper presents a new analytical method for ridge load calculations, in which the ice was assumed to be elastic-perfectly plastic and the upper bound theorem in the plasticity limit analysis was employed. To verify the applicability of this method, a model test program was conducted in a synthetic ice model basin. Ridges of various sizes, lengths, and orientations were embedded in uniform ice sheets and were pushed to fail against a fixed, 45° cone. Ice loads were measured in both vertical and horizontal directions. Agreement between calculated and measured loads is good.
Year: 1984