伶仃洋大桥锌-铝-稀土合金镀层钢丝腐蚀-疲劳耦合试验研究  

Experimental Research on Corrosion-Fatigue Coupling of Zn-Al-Rare Earth Alloy Coated Steel Wires of Lingdingyang Bridge

作　　者：宋神友 薛花娟 陈焕勇 朱晓雄 邹威 SONG Shen-you;XUE Hua-juan;CHEN Huan-yong;ZHU Xiao-xiong;ZOU Wei(Shenzhen-Zhongshan Link Administration Center,Zhongshan 528400,China;Jiangsu Fasten Steel Cable Co.,Ltd.,Jiangyin 214433,China)

机构地区：[1]深中通道管理中心,广东中山528400 [2]江苏法尔胜缆索有限公司,江苏江阴214433

出　　处：《桥梁建设》2022年第2期24-30,共7页Bridge Construction

基　　金：广东省重点领域研发计划资助项目(2019B111106002)。

摘　　要：深中通道伶仃洋大桥主缆采用∅6 mm 2060 MPa锌-10%铝-稀土合金镀层钢丝,为了解腐蚀-疲劳耦合作用对该类型钢丝疲劳寿命的影响,对其进行试验研究。在钢丝试样常规疲劳试验的基础上,结合伶仃洋大桥主缆的承载特征和海洋环境下的服役特点,对腐蚀疲劳试验的方法进行比选,最终采用了干湿交替腐蚀-疲劳循环耦合试验的新方法,研究不同应力变幅下主缆钢丝的腐蚀疲劳寿命、腐蚀状态及断口形态。结果表明:由于腐蚀和疲劳循环耦合作用,∅6 mm 2060 MPa锌-10%铝-稀土合金镀层钢丝抗疲劳性能有所降低,其疲劳应力变幅越大,疲劳循环次数降低幅度越大。当应力变幅为360 MPa时,在相当于4倍以上常规热镀锌钢丝盐雾腐蚀试验时间的腐蚀下,钢丝表面锈蚀超过30%,其应力循环次数为197万次,接近200万次。The main cables of Lingdingyang Bridge of Shenzhen-Zhongshan Link feature the 2060 MPa Zn-10%Al-rare earth alloy coated steel wires of 6 mm diameter.Experimental studies were conducted to examine the corrosion-fatigue cycle coupling effect on the fatigue life of the steel wires of this type.To accommodate the load bearing characteristics of the main cables of Lingdingyang Bridge and marine environment,multiple corrosion fatigue testing methods were compared,referencing the common fatigue tests on steel wire samples.The dry-wet alternating corrosion-fatigue cycle coupling test was finally selected.The corrosion fatigue life,corrosion state and fracture patterns of steel wires of main cables under diverse stress ranges were studied.The results show that due to the coupling effect of corrosion and fatigue cycles,the fatigue resistance of the∅6 mm-2060 MPa Zn-10%Al-rare earth alloy coated steel wire is reduced to a certain extent,and the reduction of fatigue cycles is more obvious when the fatigue stress amplitude is great.When the stress range is set at 360 MPa,under corrosion environment that is equivalent to four times of the duration of traditional salt spray test on hot-dip galvanized steel,the surface corrosion of the steel wires exceeds 30%,with fatigue cycles of 1970000,approximating 2000000 cycles.

关 键 词：跨海大桥 悬索桥 主缆 锌-10%铝-稀土合金镀层钢丝 腐蚀疲劳 应力循环次数 干湿交替腐蚀-疲劳循环耦合试验 

分 类 号：U443.38[建筑科学—桥梁与隧道工程] U445.73[交通运输工程—道路与铁道工程]