skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Development of a structural concept to resist impacts from multiyear ice floes, ridges, and icebergs

Conference · · Proc., Annu. Offshore Technol. Conf.; (United States)
OSTI ID:6457942

Large multi-year ice features and icebergs may have masses ranging up to 20 million tons or more and may move in the open water at speeds up to 1 knot, thus developing tremendous kinetic energy. A stepped structure concept has been developed to resist these impacts and to transfer the resultant forces and moments into the foundation thus developing a relatively high concentrated reaction force against the ice tending to spall and split it, thus causing a multi-modal failure of the ice, as well as using up kinetic energy at a relatively controlled rate. Calculated ice forces and ice failure modes will be presented. The stepped structure concept is primarily applicable to production platforms in water depths of 50 to 200 meters, which are subject to impact of large ice features such as multi-year ridges, floes, and icebergs The resulting global ice loads are reduced by 50 percent or more as compared to those developed by a vertical or a steep sided structure. Overturning moments are reduced, thus reducing maxima soil bearing values. The structure itself is efficient in its use of structural materials, and is practicable for construction in prestressed reinforced concrete or steel/ concrete hybrid construction. It has acceptable draft during tow and can carry a fully outfitted deck. It is stable during all stages of installation.

Research Organization:
Ben C. Gerwick Inc.
OSTI ID:
6457942
Report Number(s):
CONF-8405208-
Journal Information:
Proc., Annu. Offshore Technol. Conf.; (United States), Vol. 3; Conference: 16. annual offshore technology conference, Houston, TX, USA, 7 May 1984
Country of Publication:
United States
Language:
English