漭街渡深水桥梁抗震分析

漭街渡大桥为目前国内在建和已建深水桥梁中水深最大的桥梁.由于地处地震多发区,必须研究其在地震作用下结构在水中的地震反应及水体对结构地震响应的影响程度.根据深水桥梁特点,基于线性辐射波浪理论和特征函数扩展法分别得到考虑弹性结构流固耦合时空心墩内部和外部水体作用于桥墩有限元节点上动水力的近似解析表达后,采用混合分析方法建立了深水桥梁地震分析的有限元模型.计算分析结果表明,水体对漭街渡深水桥梁动力特性及地震反应的影响较为显著不能忽略.

SEISMIC RESPONSE OF MANGJIEDU DEEP-WATER BRIDGE

Mangjiedu deep-water bridge locates in an area where earthquakes occur quite frequently, therefore the hydrodynamic force on the piers induced by the earthquake will be considerable. A semi-analytical and semi-numerical approach for earthquake induced hydrodynamic force on elastic rectangular hollow bridge pier was developed. Based on linear radiation wave theory, the interior and exterior hydrodynamic forces on pier were got by eigen function expansion method. This method avoided solving fluid-solid model directly, and was efficient for bridge engineering. The modal analysis, spectrum analysis and transient analysis were introduced respectively and the results showed that the influence of hydrodynamic force can not be neglected for Mangjiedu bridge because the 168 meter high piers could almost all in water.