腐蚀环境下斜拉索承载力评价模型研究

Study on the bearing capacity evaluation model of stay cables in corrosion environment

为了分析和确定腐蚀环境下的斜拉索可靠度及斜拉索换索时机,在已有的斜拉索腐蚀分布模型研究的基础上,建立了腐蚀钢丝的有限元模型。通过计算,分析了腐蚀程度对钢丝承载力的影响,并拟合得到钢丝承载力与腐蚀程度之间的关系式。研究结果表明:腐蚀程度对拉索钢丝承载力的影响显著,钢丝的承载力随腐蚀程度的加深不断下降。结合并列模型理论,提出了腐蚀斜拉索承载力的退化模型,并利用该模型,分析了实际工程中某斜拉桥拉索的可靠度随腐蚀程度和服役年龄的变化,验证了该模型的应用价值。

In order to provide a reference for the reliability analysis of staycables and the determination of the time of cable replacement in corroded environments,the finite element model of the corrosion steel wire is established on the basis of the existing study on the corrosion distribution model of the cable stayed cable.The influence of corrosion degree on the bearing capacity of steel wire was analyzed through the calculation results,and the relationship between the bearing capacity of steel wire and the degree of corrosion was obtained.The results show that the degree of corrosion has a significant effect on the bearing capacity of the cable.The bearing capacity of the steel wire was decreased continuously with the increase of corrosion degree.Finally,based on the above theory and combined with the parallel model theory,the degradation model of the bearing capacity of the corroded cable is put forward,and the reliability of the longest cable Z17 in apractical cable-stayed bridge with the degree of corrosion and service age is analyzed by using this model,and the application value of the model is demonstrated.