高速列车引起的深水桥墩流固耦合的振动分析

摘要

To research the effect of water on the vibration characteristics of bridge pier structure, this study built a bridge pier-water fluid-solid interaction finite element model based on the computing platform of ANSYS, calcu-lated the natural frequency of the bridge pier at different water depths, and then analyzed effects of water depths on the bridge pier vibration characteristics under the role of high-speed train. The conclusions drawn from the analysis were:when the water depth was less than 50%height of the pier, the natural frequency of bridge pier did not decrease significantly;when the water depth was higher than 50%height of the pier, the natural frequency of bridge pier reduced obviously;under high-speed train, with the increase of the water height the time of the longitu-dinal displacement extreme appeared lingeringly and the longitudinal acceleration of the pier increased. There-fore, it concludes that water structure has obvious effects on the static and dynamic vibration characteristics of bridge pier, which can not be neglected.%为研究水体对桥墩结构振动特性的影响，以ANSYS为计算平台，建立了桥墩-水流固耦合有限元模型，计算了不同几何尺寸和淹没比情况下桥墩的自振频率，分析了桥墩在高速列车作用下，不同水深对其振动特性的影响。分析后得出结论：当水体深度小于墩高50%时，桥墩的自振频率降低不明显；当水体高度大于墩高50%时，桥墩自振频率出现明显降低。高速列车作用下，桥墩墩顶纵向位移出现极值的时间，随淹没比的增加向后推迟；桥墩墩顶纵向加速度随淹没比的增加而增加。因此，高速列车作用下，水体对于涉水铁路桥梁桥墩的自振与动力振动特性有着明显的影响，且这种影响不可忽视。