海上固定式基础设计环境参数确定的极值联合概率分布方法

An Extreme Value United Probablity Distribution Method of Design Circumstance Parameters for Offshore Permanent Foundation

环境参数的合理选取是海上固定式基础结构设计的关键内容。该文基于三元logistic嵌套模型分析并拟合了某一近海风电场的年极值风速、有义波高及平均周期实测数据,发现该模型能较好的描述年极值风速、有义波高及平均周期的联合分布。同时结合极值联合概率分布与等效荷载效应原理,以最大倾覆力矩值为标准,得到不同重现期下的设计环境参数,并与传统的设计标准进行了比较。结果表明,该文使用地方法较好地反映了风速、波高、周期对固定式基础结构的联合作用,并合理地降低了其设计环境参数。

Determining circumstance parameters in reasonable way is a major part of the design for offshore permanent foundation structure.This paper bases on three dimension logistic nest model,analyzes the measure data of wind velocity,significant wave height and mean period in one inshore area.The result shows that the united distribution of annual extreme wind velocity,significant wave height and mean period is suitable described by three dimension logistic nest model;Combining the united probability distribution of extreme value and equivalent load effect theory,and taking maximum overturning moment as the determining standard,gets the design circumstance parameters in different return period and compare the result with traditional design standard.The results show that the method in this paper suitably describes the united affection of wind,wave and period to offshore permanent foundation structure,and reduces the design parameters reasonably.