近海平台贮备强度的概率评估

A PROBABILITY EVALUATION ON RESERVE STRENGTH OF OFFSHORE PLATFORM

应用极限强度的概率分析理论，以国内某现役近海石油平台结构为工程背景，对三维大型导管架结构系统的贮备强度及安全裕度进行了系统研究。针对平台结构特征，对管节点的冲剪效应、管的局部与整体屈曲失效模式、结构失效的工程判据、系统破坏路径枚举等给予了充分讨论，构造了关于截止破坏路径枚举的工程优化准则算法，结合载荷增量方法，完善了大型导管架系统贮备强度及安全裕度的概率评估方法，并开发成相应的工程分析软件。由实际算例，对算法的合理性及可行性进行了论证分析，数值结果表明与实际结构工程的使用维护结论相符。该研究为大型导管架结构系统的安全性评估是有效及可靠的。

On the basis of probabilistic evaluation theory of ultimate strength analysis,the sophisticated and systematic studies on reserve strength and safety margin of 3D large scaled jacket structure system,under the background of an in-serve off shore platform were made in this paper. Stressed on the platform structure characteristics,this work paid more attention and discussion to pushing-shear effect of tubular joints,local and bulky tubular buckling failure pattern,engineering structure collapse criteria and structural system failure paths searching strategy,etc. An effective engineering optimal criterion for cutting off failure model enumeration was proposed. With load incremental method, a complete probabilistic evaluation procedure of reserve strength and safety margin for the mentioned structural system was constructed and also programmed. A practical engineering example was used to check its reasonableness and feasibility of the above algorithm procedure,and the numerical results in Table 2 were identified in fairly good agreement with some maintenance situations in engineering practice,which shows that the proposed safety evaluation procedure is effctive and reliable.