大跨双塔斜拉桥的动力特性与地震响应分析

结合某大跨双塔斜拉桥工程设计实例,采用大型有限元软件ANSYS建立了三维有限元计算模型,分析了该桥的动力特性,并采用反应谱法进行了地震反应分析。研究结果表明:由于采用了半漂浮斜拉桥体系,主梁梁端位移较大,极易造成主、引桥间碰撞且对两端伸缩缝不利,可采用弹性约束或设置阻尼器等措施来限制主梁梁端位移。

Analysis of Dynamic Characteristics and Seismic Response of Long Span Cable-stayed Bridge with Double Towers

Based on an engineering design case of a long span cable-stayed bridge with double towers,the three-dimensional finite element models was built by ANSYS software and the dynamic characteristics of the bridge was analyzed.The seismic response analysis was performed by employing response spectrum method.The characteristic of seismic response of the bridge was discussed.The results indicate that the large displacement of the girder is caused by the half-floating cable-stayed bridge system.It may cause pounding between main span and approach span,and it is also harmful to the expansion joints.The measures such as elastic restraint or dampers can be used to restrain the displacement of the girder.