DESIGNING OFFSHORE STRUCTURES TO OVERCOME COLLISIONS

Every offshore platform should statistically expect to sustain a minor collision after about two years of productive service. In such a collision, up to 0.5MJ of energy could be transferred to the platform. Using this collision energy value, it was calculated that impact damage rather than the topsides loading condition governs the size and disposition of elements in the upper part of a fixed steel platform. The author therefore believes that impact resistant platforms can be designed by utilizing some or all of the following design principles: reserve strength, where elements in the jacket continue to carry loads after impact; redundancy, where braces carry leg loads when the legs are impacted; confinement, where damage is confined to the struck element; and bridging the gap, where fenders and fillers enhance leg strength. Although the lenient value of 0.5MJ was used as the impact energy for the theoretical derivation, the author recommends the use of an upper bound (14MJ) approach as an additional criterion for designing impact-resistant platforms.

• Supplemental Notes:
  • Journal article reprint; Also published in Offshore Engineer, August 1982, pp.95-98
• Authors:
  • Donegan, E
• Publication Date: 1982

Media Info

• Pagination: 3 p.

Subject/Index Terms

• TRT Terms: Design; Offshore platforms; Shock resistance
• Uncontrolled Terms: Design criteria; Impact strength
• Old TRIS Terms: Collision resistance; Platform legs; Platform rammings; Platform safety
• Subject Areas: Bridges and other structures; Design; Marine Transportation;

Filing Info

• Accession Number: 00661035
• Record Type: Publication
• Source Agency: Maritime Technical Information Facility
• Files: TRIS
• Created Date: Jul 21 1994 12:00AM