不同薄壁墩间距的连续刚构桥动力响应分析

Dynamic response analysis of continuous rigid frame bridge with different thin-wall Piers

以某连续刚构桥为研究对象,用有限元分析程序Midas civil构建结构模型,以时程分析的方法研究了墩间距对连续刚构桥的动力特性及地震反应的影响。结果表明:墩间距对桥梁的自振频率有一定影响,但对自振特征影响不大;当墩间距较小时(<3 m),主梁的弯矩及剪力、墩底弯矩及剪力、跨中弯矩及竖向位移、梁端位移均没有明显地变化;当墩间距达到3 m,即主跨径的3/40时,梁端弯矩及剪力有较为明显地变化。

Taking a continuous rigid frame bridge in a city as a research object, the finite element analysis program Midas civil is used to construct the structural model. The influence of the pitch on the dynamic characteristics and seismic response of the continuous rigid frame bridge is studied by means of time history analysis. The results show that the pitch of the pier has a certain influenceon the natural frequency of the bridge, but it has little effect on the vibration characteristics. When the pitch is small（ 3 m）, the bending moment and shear force, the bending moment and the vertical displacement, the beam end displacement are not significantly changed, but when the pier spacing reaches 3 m, that is, the main span of 3/40, the beam end moment and shear force has more obvious changes.