大跨度公轨两用单索面钢桁梁斜拉桥地震响应参数分析

Analysis of seismic response parameters for rail-cum-road cable-stayed bridge with long span,single cable plane and steel truss girder

为研究公轨两用大跨度单索面钢桁梁双塔斜拉桥结构参数对地震响应的影响,以某公轨两用大跨度单索面钢桁梁双塔斜拉桥为背景,使用Midas软件建立不同结构参数的多个模型,使用反应谱法,分析索塔刚度、钢桁梁刚度、辅助墩数量以及结构体系对于该类桥梁地震作用的影响.研究结果表明:桥梁抵御横向地震荷载的能力相对较弱,应采取措施弥补,天梭型索塔对抗弯和抗震强度有一定的保障;地震作用下,漂浮体系的抗震性能较弱,刚构体系的抗震能力要弱于半漂浮体系和塔梁固结体系,塔梁固结体系的抗震性能表现最好;提高主梁的刚度和科学的增设辅助墩可以减缓公轨两用大跨度单索面钢桁梁斜拉桥地震响应.

In order to study the influence on the seismic response of structural parameters for rail-cum-road cable-stayed bridge with long span,single cable plane and steel truss girder,such a rail-cum-road cable-stayed bridge is studied.The software Midas is used to build multiple models with different structural parameters,and the response spectrum method is used to analyze the influence of cable tower stiffness,steel truss girder stiffness,the number of auxiliary piers and structural system on the seismic response of this kind of bridge.The results show that the bridge has a relatively weak ability in resisting lateral seismic load,so measures should be taken to improve it,for which cable tower with tissot shape may be able to help since it has high flexural and shock strength.The floating system shows weak anti-seismic performance.The anti-seismic performance of the rigid frame system is weaker than that of the semi floating system and the tower beam consolidation system which shows the best performance.Increasing the stiffness of the main girder and adding auxiliary piers scientifically can slow down the seismic response of the long-span cable-stayed bridge with single cable plane and steel truss girder.