A reliability method (FOSM) has been used to assess the probability of sliding failure of the 33 years-old island caisson breakwater sheltering an oil terminal at Gela (Italy). The vertically composite structure is placed in just 13 m depth upon a weak silty seabed. It has experienced settlements of about 1 m, toe scour around 2 m and degradation of the slender reinforced superstructure, especially damaged after a severe storm on 24 November 1991. On the basis of new detailed wave climate studies and field investigations a modern probabilistic analysis has been performed to verify the actual risk of failure, particularly against sliding over the rubble mound foundation due to wave loads. A new formulation of the failure function as been derived introducing new expressions for the pressure coefficients in the Goda formula. A detailed sensitivity analysis of the failure probability with the caisson geometry has also been pewrformed.

Risk Analysis of the Vertical Offshore Breakwater at Gela, Italy

PASSONI, GIUSEPPE;FRANCO, LEOPOLDO;
1997-01-01

Abstract

A reliability method (FOSM) has been used to assess the probability of sliding failure of the 33 years-old island caisson breakwater sheltering an oil terminal at Gela (Italy). The vertically composite structure is placed in just 13 m depth upon a weak silty seabed. It has experienced settlements of about 1 m, toe scour around 2 m and degradation of the slender reinforced superstructure, especially damaged after a severe storm on 24 November 1991. On the basis of new detailed wave climate studies and field investigations a modern probabilistic analysis has been performed to verify the actual risk of failure, particularly against sliding over the rubble mound foundation due to wave loads. A new formulation of the failure function as been derived introducing new expressions for the pressure coefficients in the Goda formula. A detailed sensitivity analysis of the failure probability with the caisson geometry has also been pewrformed.
The Proceedings of The Seventh (1997) International OFFSHORE AND POLAR ENGINEERING CONFERENCE
188065332X
Vertical Breakwater, Stability, Reliability, FOSM
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/693856
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