Evaluation of uncertainties in loadings on offshore structures due to extreme environmental conditions

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Journal of Offshore Mechanics and Arctic Engineering; (United States)

DOI:https://doi.org/10.1115/1.2920118· OSTI ID:5647777

Bea, R G ^[1]

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1. Univ. of California, Berkeley, CA (United States). Dept. of Civil Engineering

This paper summarizes results from a Canadian Standards Association (CSA) sponsored study of the uncertainties associated with extreme (1,000 to 10,0000-yr return periods) environmental loadings acting on offshore structures (Bea, 1991). The evaluations of the loadings addressed loading effects that resulted from dynamic and nonlinear interactions of the structures. Loading uncertainties were organized and characterized in two categories: (1) inherent randomness (aleotory uncertainty), and (2) analytical variability (epistemic uncertainty). The study addressed the global ultimate limit state performance of three structures designed according to the provisions on the draft CSA guidelines (1989a, 1989b) for offshore structures: (1) a concrete Gravity Base Structure (GBS) located off the East coast of Canada (Hibernia), (2) a steel pile template located on the Scotian Shelf off Sable Island, and (3) a caisson retained island located in the Mackenzie Delta area of the Beaufort Sea (Amuligak). The results of this study indicate that, based on presently available information and data, it is often not possible to develop unambiguous characterizations of uncertainties. The different technical communities that background environmental conditions and forces (storms, earthquakes, ice) recognize and integrate these uncertainties into loading characterizations in different ways.

• OSTI ID: 5647777
• Journal Information: Journal of Offshore Mechanics and Arctic Engineering; (United States), Journal Name: Journal of Offshore Mechanics and Arctic Engineering; (United States) Vol. 115:4; ISSN 0892-7219; ISSN JMOEEX
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
423000* -- Engineering-- Marine Engineering-- (1980-)
DYNAMIC LOADS
FUNCTIONS
GRAVITY WAVES
OFFSHORE PLATFORMS
RESPONSE FUNCTIONS
SAFETY STANDARDS
STANDARDS
WATER WAVES
WAVE FORCES