Abstract: By conducting the artificially accelerated corrosion test of galvanized steel cable under the effect of acid rain / load coupling, three kinds of loading patterns were applied for the stayed cable, which included alternating load, static load and no load, and the relationship between three kinds of loading patterns and corrosion rate was obtained. The characteristics and mechanism of strand stress corrosion fatigue damage were also discussed. Numerical simulation for stayed cable in different corrosion conditions was carried out by ANSYS finite element software, and the effect of the strand uniform corrosion and surface corrosion pitting depth on the steel equivalent stress distribution state was analyzed. Studies show that: the corrosion rate of the strand in accelerated corrosion test and the components under complex loads is higher in the same corrosive environment. In the preperiod of corrosion test, stress corrosion and corrosion fatigue have little effect on tensile strength; the tensile strength has no significant difference among three loading patterns. In the middle and later periods of corrosion test, the tensile strength starts a sharp decline, and the tensile strength of alternating stress loading specimens appears the phenomenon of a short increase; the more serious corrosion the strand, the greater the steel strand stress near surface corrosion pits during its service time.

Key words: bridge engineering, stayed cable, acid rain environment, alternating loading, stress corrosion

摘要： 通过开展拉索镀锌钢绞线在酸雨环境/荷载耦合作用下的人工加速腐蚀试验，对斜拉索施加交变荷载、静态荷载和无荷载，得出3种加载方式与腐蚀速率的关系，并论述了钢绞线应力腐蚀疲劳损伤的特点与机理；采用ANSYS有限元软件对不同腐蚀情况下的斜拉索进行数值模拟，分析了钢绞线均匀腐蚀、表面蚀坑深度对钢丝等效应力分布状态的影响。研究表明：加速腐蚀试验中的钢绞线，受到复杂荷载的构件在同等腐蚀环境中的腐蚀速率更高；腐蚀试验前期，应力腐蚀和腐蚀疲劳对抗拉强度的影响不大，3种加载方式之间的抗拉强度无明显差异，腐蚀试验中后期，抗拉强度开始急剧下降，交变应力加载试件出现抗拉强度短暂提高的现象；钢绞线腐蚀越严重，其在役状态时钢绞线表面蚀坑附近的应力就越大。

关键词: 桥梁工程, 斜拉索, 酸雨环境, 交变荷载, 应力腐蚀