COMBINED WAVE-ICEBERG LOADING ON OFFSHORE STRUCTURES

The Canadian Standards Association has developed and published a code for the design and construction of fixed offshore structures. This cod e has been subjected to a comprehensive verification process which has identified several issues warranting further study. One of these rela tes to the combined effects of wave and iceberg collision loading. At present, this combination is treated by the use of a load combination factor specified in the Code. The present paper describes a recent stu dy which was undertaken to determine the appropriateness of the recomm ended value of the load combination factor. The study involves a numer ical analysis in which loads due to waves alone, an iceberg alone, and an iceberg and waves in combination have been calculated for a range of iceberg and wave parameters. These results have been applied to a f irst-order reliability analysis in order to study the force levels cor responding to an annual probability of 10(-4) or to the onset of globa l sliding with an annual probability of 10(-4). The paper thereby make s recommendations for load combination factors applicable to combined wave-iceberg loading.