Directional sea state criteria for deepwater Gulf of Mexico compliant towers

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:182684

Leonard, J S; Morrison, D G ^[1]

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1. E and P Technology Co., Houston, TX (United States). Ocean Research and Development

Directional sea state criteria have been developed for deepwater compliant towers which accommodate for the fact that the loading intensity of extreme Gulf of Mexico (GOM) storms and their resulting structural responses change with direction. The methodology used results in a more consistent approach to establish structural strength (in different directions) relative to the preferred directions of extreme storms. In the past, structures have been designed to withstand the omni-directional extreme event from all directions although it is very unlikely to occur from most directions. Structures designed to the proposed directional criteria, unlike structures designed to omni-directional criteria, must carefully assess the impact of their directional orientation. The directional criteria include the effects of hurricanes combined with Loop Currents, random waves, sea state directionality, and current blockage. The presented approach to directional wave criteria resulted in a drop of the severity of the extreme storm sea states from previously established intensities. A noticeable savings in steel costs accompanies this drop. Both the conventional (omni-directional) and the proposed (by-direction) methods use 3-dimensional wave theories. The new by-direction technique should not be confused with adding spread wave theory to criteria development. Rather, the authors introduce a methodology to capitalize on the storm sea state heading directionality (i.e. differences in storm intensities for different headings).

• OSTI ID: 182684
• Report Number(s): CONF-950695--; ISBN 0-7918-1306-1
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
42 ENGINEERING
DESIGN
DYNAMIC LOADS
GULF OF MEXICO
OFFSHORE PLATFORMS
RESPONSE FUNCTIONS
SAFETY STANDARDS
THREE-DIMENSIONAL CALCULATIONS
WATER WAVES
WAVE FORCES