拉索涡振下考虑车辆和温度联合作用的斜拉桥钢锚箱疲劳性能  

Fatigue performance of steel anchor box in cable-stayed bridges considering joint action of vehicle and temperature under vortex-induced vibration of stay cable

作　　者：祝志文 颜爽[1] 丁望星 廖原 ZHU Zhiwen;YAN Shuang;DING Wangxing;LIAO Yuan(Department of Civil and Intelligent Construction Engineering,Shantou University,Shantou 515063,China;Hubei Communications Planning and Design Institute Co.,Ltd.,Wuhan 430051,China)

机构地区：[1]汕头大学土木与智慧建设工程系,广东汕头515063 [2]湖北省交通规划设计院股份有限公司,湖北武汉430051

出　　处：《振动工程学报》2025年第2期268-278,共11页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(51878269,52278509)。

摘　　要：为评价运营状态下斜拉桥拉索发生大幅涡激振动时的钢锚箱疲劳性能,连续监测了某大跨斜拉桥发生涡激振动的某拉索振动加速度和钢锚箱构造细节应力,在时/频域内研究了该拉索的振动特性,以及拉索涡激振动、车辆加载和温度作用对钢锚箱构造细节应力的贡献,探究了这三种荷载对钢锚箱的加载机制,评价了这三种荷载联合作用下钢锚箱的疲劳性能。研究发现,试验斜拉索在风速2~9 m/s之间发生了明显的风致振动,观测到的面内最大加速度峰值达25 m/s^(2),为多模态参与的高阶涡激振动,面内振动明显大于面外,主振模态出现在拉索第5~17阶。温度作用虽每天仅产生一个应力循环,但在钢锚箱构造细节上产生的最大应力幅明显大于车辆应力幅;虽然车辆通行产生的应力幅较小,但一辆货车通行产生一个应力幅,应力循环次数大;拉索涡激振动惯性力施加在钢锚箱上,但在构造细节上观测到的应力水平极低,因此可完全忽略拉索涡激振动对钢锚箱应力和疲劳的影响。研究认为,钢锚箱疲劳评价需考虑温度作用,但受拉索涡激振动、通行车辆和温度作用的联合加载,在钢锚箱疲劳最不利的顶板和底板与钢箱梁外腹板焊缝桥面端,以及承压板与外腹板焊缝两端的四个构造细节处,疲劳寿命均明显大于100年。因此即使拉索发生涡激振动,该在役钢锚箱疲劳性能也满足桥梁设计要求。In order to evaluate the fatigue performance of the steel anchor box(SAB)when its stay cable experiences large-ampli-tude vortex-induced vibration(VIV)under in-service condition,continuous monitoring was conducted on a long-span cable-stayed bridge.The acceleration of the stay cable undergoing VIV and the stress at the SAB details were measured.The characteristic of stay cable vibration,as well as the stress at the SAB details due to VIV of the stay cable,vehicles loading,and thermal effects,were investigated in both time and frequency domains.Hence the loading mechanisms of VIV,vehicle loading,and thermal effects on the SAB were discussed.Based on the nominal stress method,the fatigue performance of the SAB under the joint action of VIV,vehicle loads and thermal effects were evaluated.The results show that the significant vibration of stay cable,characterized by the high-order multi-mode VIV,dominated by in-plane vibration with peak frequencies between the fifth and the seventeenth modes,occurring within a mean wind speed range of 2 m/s to 9 m/s,with observed maximum in-plane peak acceleration of 25 m/s^(2).Thermal effects significantly contribute to the maximum stress range at the SAB details,although they only generate one stress cy-cle per day.Compared to the thermal action,the stress range generated by the passage of vehicles is relatively low,but trucks pro-duce a large number of loading cycles.The inertial force generated by VIV of the stay cable applies very low stress to the SAB,making its effects on stress and fatigue negligible.It is concluded that the fatigue evaluation of the steel anchor box should consider the thermal effects.However,even when considering the combined effects of VIV loading,thermal effects and vehicle loading,the fatigue life at the critical details of the SAB—specifically the deck-side welds of the upper and lower plates to the outer web,as well as both weld ends of the bearing plate to the outer web of the steel box girder—exceeds 100 years.Therefore,the fatigue per-formance

关 键 词：斜拉索 疲劳 涡激振动 钢锚箱 车辆加载 温度作用 

分 类 号：U443.38[建筑科学—桥梁与隧道工程] U441.4[交通运输工程—道路与铁道工程]