钢桥塔涡激共振振幅允许值确定研究  

Study on Determination of Allowable Amplitude of Vortex-induced Resonance of Steel Bridge Towers

作　　者：李加武[1] 张国强[1] 张波[2] 

机构地区：[1]长安大学公路学院,陕西西安710064 [2]中国水电顾问集团贵阳勘测设计研究院有限公司,贵州贵阳550081

出　　处：《中国公路学报》2014年第3期45-50,共6页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51078038)

摘　　要：以南京长江三桥、江海直达桥方案Ⅰ以及江海直达桥方案Ⅱ为例,从主梁涡激共振的应力状态出发,推算了算例钢桥塔的弯曲涡激共振允许振幅,并研究了该振幅允许值与塔高的关系,总结出以塔高为参数的桥塔弯曲涡激共振允许振幅估算公式。研究桥塔自立状态弯曲涡激共振允许值时,参照钢主梁竖向涡激共振振幅达最大允许值时由振动引起的主梁控制截面竖向弯曲应力值占主梁钢材允许弯曲应力的比值,将该比值引入桥塔弯曲涡激共振振幅允许值的研究中。最后进行了算例桥塔的气弹模型风洞试验。结果表明:钢主梁竖向涡激共振弯曲应力最大允许值与主梁钢材允许弯曲应力的比值为一定值,钢桥塔弯曲涡激共振振幅达最大允许值时,振动引起的塔控制截面弯曲应力与塔钢材允许弯曲应力的比值也可认为是一定值;桥塔弯曲涡激共振最大允许幅高比约为0.12%;研究结果可为大跨桥梁索塔涡激共振允许振幅的确定提供参考。The authors took Jianghai Zhida Bridge plan Ⅰ , Jianghai Zhida Bridge plan Ⅱ and 3rd Nanjing Yangtze River Bridge as examples. Based on the stress state of the main beam, the allowable amplitudes of bending vortex-induced resonance of steel bridge towers were calculated and the relationship between the allowable amplitudes and tower height was studied. An estimation formula for the allowable amplitudes of bending vortex-induced resonance of steel bridge towers were determined with the parameter of tower height. For self-supporting bridge tower, the allowable amplitude of bending vortex-induced resonance of the tower was estimated. When the allowable amplitude of vertical vortex-induced resonance of the beam reached its maximum value, a ratio between the vertical bending stress at the key section and the permissible bending stress of the steel for the beam was used for the estimation. The wind tunnel tests for aeroelastic models of bridge towers were conducted. The results show that the ratio between the maximum allowable bending stress produced by main beam vertical vortex-induced resonance and the allowable bending stress of the steel for the beam is a certain value. When the amplitude of the towers produced by the tower vortexqnduced resonance reaches the maximum allowable values, the ratio between the vertical bending stress at the key section and the allowable stress of the steel for the beam is also a certain value. The maximum allowable amplitude ratio of bending vortex-induced resonance of steel bridge towers is about 0. 12%. The results can provide reference for the determination of allowable amplitude for vertex-induced resonance of large-span bridge towers.

关 键 词：桥梁工程 钢桥塔 风洞试验 涡激共振 允许振幅 允许弯曲应力 

分 类 号：U441[建筑科学—桥梁与隧道工程]