既有桥梁外贴CFRP加固后剩余使用寿命预测

Predicting remaining service life of existing bridges strengthened with CFRP

根据时变可靠性理论提出基于承载力可靠性的既有桥梁外贴碳纤维布加固后结构构件的剩余使用寿命预测方法,讨论了钢筋锈蚀、混凝土强度、纤维布加固耐久性以及荷载效应等因素变化对加固后既有桥梁结构构件承载力的影响.在国内外纤维片材加固混凝土结构的耐久性试验基础上,提出在加固后可以不考虑纤维布材料的老化及其纤维布材料与混凝土粘结界面的退化,使加固后钢筋混凝土构件承载力极限状态可靠度分析得到简化.结合一座实际桥梁工程进行了加固后可靠度计算,并对其剩余使用寿命进行预测.

An assessment criterion for remaining service life of existing concrete structures is put forward based on reliability theory. The influence mechanism of bridge resistance after reinforcement is discussed. According to the durability research and corresponding experiments, the aging of CFRP material and the degradation of the interface between CFRP and concrete can be ignored. Therefore, the calculation of reliability index can be simplified. The above methods are applied to reliability assessment of a practical example. The bridge is a PC structure. The reliability analysis of load-bearing capacity with time-dependent resistance after reinforcement bonding externally CFRP is made.