覆冰斜拉索驰振稳定性的理论研究  

Theoretical analysis of galloping stability for stay cables with Iced accretions

作　　者：李寿英[1,2] 黄韬[2] 叶继红[1] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096 [2]湖南大学风工程试验研究中心,长沙410082

出　　处：《振动与冲击》2013年第1期122-127,共6页Journal of Vibration and Shock

基　　金：东南大学混凝土及预应力混凝土结构教育部重点实验室开放课题资助;国家自然科学基金项目资助(50708035)

摘　　要：覆冰斜拉索可能会发生驰振振动并影响到斜拉桥的安全。在进行风洞试验对6种覆冰拉索模型测力的基础上,推导了覆冰拉索1阶模态驰振的运动微分方程,并采用龙格-库塔法进行求解,得到了拉索的驰振响应规律。以海南洋浦大桥为工程背景,研究了中跨最长拉索M18的驰振临界风速,研究了覆冰长度、拉索阻尼比等对驰振临界风速的影响。结果表明,在新月形、扇形和D形覆冰条件下,中跨最长拉索M18的驰振临界风速在10-15 m/s范围内,远小于基本风速,存在发生驰振可能性;随着阻尼比的增加、覆冰长度的变短以及拉索长度的变短,驰振临界风速增加。Galloping vibration may take place on stay cables with iced accretions, it affects the safety of cable- stayed bridges. Firstly, wind tunnel tests were conducted to measure the mean aerodynamic force coefficients on six kinds of cable models with iced accretions. Then, an equation of motion of their first mode of galloping vibration was derived, and their galloping responses were obtained by solving the equation with Runge-Kutta method. Taking Yangpu Bridge in Hainan province, China as an engineering background, the galloping critical wind velocity was investigated in detail, the effects of cable damping ratio and iced accretion length on the galloping critical wind velocity were alsb studied. The results showed that the galloping critical wind velocities of the longest stay cable M18 at the mid-span of Yangpu Bridge under different conditions of iced accretions are 10 to 15 m/s, they are far less than basic wind speeds, this cable has the risk of galloping vibration; moreover, the galloping critical wind velocity increases with increase in the cable damping ratio and decrease in the iced accretion length.

关 键 词：斜拉索 覆冰 驰振临界风速 理论研究 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]