基于超越概率的海堤防御标准理论探讨

Theoretical Discussion on Defense Standard of Sea Dike Based on Exceedance Probability

针对海堤防御标准确定的重要性及复杂性,引入超越概率理论,提出了双灾害因素的组合超越概率理论分析方法,推导了双灾害因素组合重现期关系,并对海堤破坏因素进行物理分解分析后提出一段时间(使用期)内其遭遇出现的理论超越概率,进而从物理层面探讨了重现期关系。结果表明,遭遇双灾害因素事件,对确定的可靠度可采取多种重现期组合方式满足;当重现期组合关系满足1∶2.18时,双灾害因素同时出现的概率最大。

Aiming at the importance and difficulty of determination defense standard of sea dike,theoretical analysis with combination of two disasters factor is discussed based on exceedance probability theory.And combined relationship of return periods with two disasters is deduced.According to the decomposition and physical analysis of destroyed factors of sea dike,the theoretical exceedance probability in a period of time or life time is calculated.Finally,the relationship of return period is also discussed from physical layer.The results shows there are several combined relationships of return period for meeting deterministic confidence level when two disasters event appears;and it is the maximal probability that two disasters appear simultaneously when combined relationship of return periods attains 1∶2.18.