中文摘要：

针对季节性冰冻地区的海工结构耐久性失效特点以及结构耐久性具体要求,从失效率与可靠度的关系入手,运用随机场理论,综合考虑正负峰值温度差、氯离子临界浓度与预应力的影响,提出了冻融条件预应力结构氯盐侵蚀的可靠度分析模型。通过算例,讨论了离散数目对失效概率的影响,并对氯离子浓度、保护层厚度等相关随机变量进行了灵敏度分析。结果表明：运用随机场分析结果与JC法及实用分析法得到的数值结果相近;基于所给出的结果,有望为工程应用中的可靠度分析提供合理的前期准备。

英文摘要：

Based on the characters of durability failure of marine structures and requirements on structural durability in seasonal ice, a reliability model of prestressed structures with chloride attack and cyclic freeze-thaw was put forward from the relationship of failure rate and reliability as well as random field theory, according to the influence of positive and negative peak temperature difference, chloride concentration and prestressing force. The influence of discrete variable number to failure probability was discussed and the sensitivity of correlation random variables was analyzed, such as chloride concentration, cover and so on. It is showed that the results are agreed well with the numerical results of the JC method and the practical analytical method. The results reported herein could provide reasonable preparations for the reliability analysis in engineering application.