Level ice interaction with sloping and conical offshore structures

• Main Author: Bruce, Jonathon E.F. (Jonathon Edward F.)
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2009
• Subjects: Arctic; ice covered waters
• Online Access: https://research.library.mun.ca/8846/; https://research.library.mun.ca/8846/1/Bruce_JonathonEF.pdf

The use of sloping sided or conical structures is often a favorable design option for structures placed in ice covered waters. An understanding of the mechanics involved during level ice interaction with conical or sloping sided structures is necessary for safe structural design in environments where ice cover is present. This work provides a review of the failure mechanics involved during an ice interaction with a conical or sloping sided structure and the methods which have been developed to model these types of interactions. -- The sensitivity of the ice loads, estimated by the Croasdale Model, to the variation in input parameters has been studied in this work. From this analysis, it was determined that if a rubble pile was present on the structure, the flexural strength of ice was not a significant factor affecting the ice load. There were however a number of scenarios which were outlined for which the flexural strength of ice was of significance. A ship ramming event is one such scenario for which the flexural strength of ice plays a significant role in limiting the maximum ice load. The maximum ice load occurs as a crushing failure on the bow of the ship, which is limited by flexural failure due to the weight of the vessel on the ice feature. Another scenario for which the flexural strength of the ice may dominate involves the use of conical structures in the Arctic. Here, designers are concerned with thick multiyear floes interacting with large conical structures. In this scenario, ride up is likely to occur with limited rubble formation due to the dissipation of kinetic energy, thus making the flexural strength of the ice a critical component affecting the design load. Further to this, the scale of the interaction has been found in this work to be a critical component affecting the flexural strength of ice, which is due to the presence of a size effect. -- The results presented in Chapter 3 show that the methodology used to predict the flexural strength of ice based on brine volume alone may well lead to ...