中文摘要：

导管架平台空间造型复杂,杆件和节点数量繁多,局部冗余度虽然高但总体分布不均匀。同时,平台质量大多集中于上部结构,局部构件的破坏可能导致结构在重力载荷作用下发生连续性倒塌。本文在导管架平台常遇的冰工况载荷作用下,对移除各个构件后的缺陷结构进行推覆分析,得到各构件重要性指标,依此判断每个构件的重要性;分析不同首失效构件导致的结构薄弱路径,从而确定结构的最薄弱路径和路径起始构件位置;进而,在保证总用钢量不变的条件下,调整构件截面设计,实现结构薄弱环节的调控。研究表明：通过构件重要性分析的方法,可以较有效地确定结构薄弱路径;通过调整薄弱路径首个构件的方法,可以实现薄弱路径的调整,结构的极限承载力提高10%以上,极限变形降低10%左右。

英文摘要：

Space configuration of a jacket offshore platform is complex with numerous of members and joints. The partial redundancy of structure is high, but the overall distribution is uneven. Meanwhile, the mass of the structure is mostly concentrated in the upper deck structure. Damage to local members progressively leads to the collapse of the entire structure under the influence of gravity. We performed nonlinear pushover analysis on the defect structure after removing each member by using the conventional encountered ice condition as an environmental factor. The importance of each member is evaluated by the obtained component importance index; weak paths caused by differ- ent first-to-fail members were analyzed to determine the weakest path in the structure and the location of the starting member in said path. Then, the weak path of the structure was regulated by adjusting the cross sections of a few members on the basis of the component importance index under the condition of constant total steel mass. The main achievements are as follows ： effective identification of structural weak paths by component importance analysis, regulation of the weak path by adjusting the starting member in the path, and 10% increase in the ultimate bearing capacity of the structure accompanied by a 10% decrease in the ultimate deformation.