Structural Reliability Assessment of Offshore Platforms Under Hurricane Events

This paper presents a structural reliability assessment method to quantify the probability of platform failure for Trinidad offshore platforms subjected to hurricane events. Platforms are modeled as a series system composed of the topsides and jacket including foundation. The platform failure limit state function is defined in terms of environmental load and platform capacity. The platform capacity is evaluated by non-linear pushover analysis using USFOS program. A parametric relationship of wave load as a function of wave height is derived based on the offshore extreme environmental data. The first order reliability method (FORM) is used to estimate the annual failure probability. The relationship between the probability of platform failure and the reserve strength ratio (RSR) of platforms is investigated. The assessment results could be used to evaluate the level of risk associated with hurricane hazards and may be incorporated into the risk-based underwater inspection (RBUI) program as part of the structural integrity management (SIM) process.