Abstract: Offshore production platforms in Bohai Gulf experience ice loading for more than three months each year.The ice load on a platform is much larger than any other environmental loads such as those from waves,current,wind or even earthquake.Therefore,reliability analysis,especially fracture reliability analysis,for the design of fixed production platforms in ice environment or under extremeice-loads is required to be conducted.This paper develops a reliability model to calculate the residual strength concerned with temperatures.It gives a probability distribution of fracture toughness CTOD valueδcwhich accounts for the residual strength of the components at different temperatures.The probability distribution of the maximum stress in the component Which depends on the ice thickness and ice compression strength is also given.According to this reliability model,a calculation method for the reliability of platform components is presented and a computation example is given to show the assessment process.

Key words: offshore, production, platform, fracture, reliability, assessment, ice load

摘要： 我国渤海每年约有三个多月的结冰期,冰与海上采油平台的相互作用,远较波浪为甚.因此,冰区固定采油平台的设计以及对服役期平台的评估,均需进行可靠性分析,而且主要是极端冰载作用下断裂的可靠性分析.文章首先建立了考虑温度效应的剩余强度的可靠性计算模型;然后给出了决定构件剩余强度的断裂韧性CTOD值δc的不同温度下的概率分布;同时还给出了取决于冰厚及海冰强度的构件上最大应力的概率分布;最后,根据计算模型,给出了计算平台构件可靠度的方法,并结合渤海八号平台评估的计算实例,对在役海上采油平台的整体系统,进行了安全可靠性分析.

关键词: 海上, 采油, 平台, 断裂, 可靠性, 评估, 冰载