【摘要】 斜拉桥的拉索在长期承受各种荷载的过程中，会产生不同程度的损伤，导致其耐久性下降，进而影响斜拉桥的力学性能和安全性。长期服役的斜拉桥拉索的更换顺序和优化，成为亟需关注和解决的理论和工程问题。为了初步确定斜拉桥拉索的更换顺序，将独塔斜拉桥等效为含拉索的多跨弹性支撑连续梁体系，并进行力学分析。引入斜拉桥竖向支撑刚度的概念，假设独塔斜拉桥主梁具有适当的刚度（并非无穷大），且两边支座为铰接，推导出独塔斜拉桥的竖向支撑刚度理论公式。在此基础上，考虑锈蚀和疲劳对竖向支撑刚度的影响，提出了考虑拉索耐久性损伤的支撑刚度修正公式。为了评价和优化斜拉桥拉索更换方案，提出了一种综合评定方法，考虑了索力、主梁弯矩、主梁位移、主塔弯矩以及主塔水平位移等多指标。以某独塔双索面斜拉桥为实例，通过计算斜拉索竖向支撑刚度初步确定拉索更换顺序，采用提出的考虑多指标的拉索方案综合评定方法对3种换索方案进行分析研究，确定最优的换索方案。结果表明，由竖向支撑刚度理论公式得到的计算结果与有限元分析结果较为吻合，具有较高的精度；考虑多指标的拉索方案综合评定方法具有很强的适用性和可行性，能够准确量化各个指标，并为工程应用提供相应的理论参考。更多还原

【Abstract】 The cables of a cable-stayed bridge undergo varying degrees of damage and deterioration in durability when subjected to various loads over the long term, which in turn affects the mechanical performance and safety of the cable-stayed bridge. The optimization and replacement sequence of the cables in long-term service of cable-stayed bridges have become theoretical and engineering problems that urgently need attention and solutions. To preliminarily determine the replacement sequence of the cables, the single-tower cable-stayed bridge is equivalent to a multi-span elastic support continuous beam system with cables,and a mechanical analysis is performed. The concept of vertical support stiffness of the cable-stayed bridge is introduced,and it is assumed that the main beam of the single-tower cable-stayed bridge has appropriate stiffness,and is not infinitely rigid,and the supports on both sides are hinged. The theoretical formula for the vertical support stiffness of the single-tower cable-stayed bridge is derived. Based on this,the influence of rust and fatigue on vertical support stiffness is considered,and a modified formula for support stiffness considering cable durability damage is proposed. In order to evaluate and optimize the cable replacement scheme for cable-stayed bridges,a comprehensive evaluation method is proposed,considering multiple indicators such as cable force,main beam bending moment,main beam displacement,main tower bending moment,and main tower horizontal displacement.Taking a particular single-tower double-cable-faced cable-stayed bridge as an example,the replacement sequence of the cables is preliminarily determined by calculating the vertical support stiffness of the cables,and the proposed comprehensive evaluation method for cable replacement schemes considering multiple indicators is used to analyze three replacement schemes, determining the optimal replacement scheme. The results indicate that the calculated results obtained from the theoretical formula for vertical support stiffness are in good agreement with the results of finite element analysis,demonstrating high accuracy. The comprehensive evaluation method considering multiple indicators for cable replacement schemes has strong applicability and feasibility,accurately quantifying each indicator and providing a corresponding theoretical reference for engineering applications.更多还原