Abstract: For estimating the extreme response of the jack-up platform, a parametric method under the action of random wave loads is developed. The method approximates the extreme distribution of the stochastic response of the platform by using the shifted generalized lognormal distribution model. The model parameters are estimated by two supporting points and their exceeding probability in the adjacent tail distribution such that the size of the needed samples is reduced significantly. The extreme response analysis of a real platform shows that the proposed method has enough high numerical accuracy and needs relatively few computational costs, which is suitable for the reliability and risk assessment of the jack up platform under the action of random wave loads.

Key words: jack-up platform; extreme response; shifted generalized lognormal distribution; tail distribution