高墩大跨度连续刚构桥空间动力特性分析

Analysis for Spatial Dynamic Characteristics of High-pier Large-span Continuous Steel Structure Bridges

连续刚构桥动力特性是桥梁结构动力分析的前提和基础。以一高墩大跨度连续刚构桥为研究对象,运用有限元软件ANSYS建立其有限元模型,分析其结构参数对动力特性的影响。分析表明:1)主梁刚度增大,各阶振型频率也随之增大,且侧弯和竖弯振型的频率变化较为明显,对纵飘振型影响较小;2)桥墩刚度的变化对侧弯和纵飘频率影响较大,而对竖弯频率影响相对较小;3)纵向约束弹簧刚度对竖向和横向各阶频率无任何影响,但是可以显著增加纵向频率。

Dynamic characteristics of continuous steel structure bridges are prerequisite and basis of dynamic structural analysis for bridges. With one high-pier large-span continuous steel structure bridge as the object of research, this paper analyzes influences of its structural parameters on dynamic characteristics by establishing its finite element model by means of finite element software ANSYS. The analysis indicates that： 1 ） All-order vibration frequencies increase with increase of rigidity of girder, and frequency changes of side bending and vertical bending vibrations are more obvious and show less influence on longitudinal floating vibration mode; 2 ） Changes of pier rigidity exhibit significant influences on side bending and longitudinal floating frequency, but relatively less influences on vertical bending frequency; 3 ） Longitudinal constraint spring stiffness has no influences on all-order vertical and longitudinal frequencies, but can remarkably increase longitudinal frequency.