Author(s): Donald E. Nevel
Linked Author(s):
Keywords: No Keywords
Abstract: A state-of-the-art review is presented for iceberg impact forces on offshore structures. A detailed description is given of the expected brittle crushing failure of the ice. Since no iceberg impacts have been observed, the description was obtained from laboratory and field impact tests. Various strength theories are discussed. The drop ball test is analyzed for the constant strength and viscous strength, theories, and it is concluded that the results do not significantly differ. Therefore, the simpler constant strength theory is recommended for use. A review of the literature showed that there is very little published data on the brittle impact strength of ice particularly in regard to the so-called size effect. There are some proprietary data in the oil industry. A review is given for the analysis of an iceberg impacting a structure. The resulting deformation and motion of the iceberg, structure, and soil influence the interaction force. A review of the literature suggests that ice crushing local contact shapes and iceberg rotation are the more significant factors. A simplified equation is developed to account for the horizontal rotation of the iceberg. Since the iceberg parameters can vary over wide ranges, it is recommended that each parameter be described by a probability of exceedance distribution. A numerical method is described to obtain the probability of exceeding the impact force.
Year: 1986