斜拉索局部振动对结构地震响应的影响*
武芳文1,2,史 俊1,杨草方1,谢礼立2

(1.长安大学 公路学院,陕西 西安 710064; 2.中国地震局工程力学研究所,黑龙江 哈尔滨 150080)

斜拉桥; 斜拉索; 地震响应; 自振频率; 耦合振动

Effect of Local Vibration of Cable-stayed Bridge on Seismic Response of Structure
WU Fang-wen1,2,SHI Jun1,YANG Cao-fang1,XIE Li-Li2

(1. School of Highway,Chang'an University,Xi'an 710064,Shannxi,China)(2.Institute of Engineering Mechanics,CEA,Harbin 150080,Heilongjiang,China)

cable-stayed bridge; cable; seismic response; natural-frequency; coupling vibration

备注

以苏通长江公路大桥为研究对象,将斜拉索分成若干等长度的单元模拟斜拉索局部振动,以探讨其对结构地震响应的影响。计算结果表明:考虑斜拉索局部振动后,结构的自振频率变化较小; 由于斜拉索基频与结构基频相近,斜拉索在地震动作用下,大幅振动,同时索—梁耦合振动明显,主梁和主塔内力降低,主塔根部弯矩明显减小。

Taking the Sutong Bridge as the research object,one cable is divided into a number of equal length elements to simulate the local vibration of cables in order to study the effect of cable vibration on structure seismic response. The calculation results show that the introduction of local cable vibration leads to a small change of the structural natural-frequency. Because the natural-frequency of the cable is similar to the natural-frequency of the structure,the amplitude of the cable is large under the earthquake motion,and the coupling vibration of cable-deck is obvious,the internal forces of girder and tower is decreased,especially the bending moment of tower root decreases obviously.