强震作用下冰水域桥墩动力响应研究分析

Research on dynamic response of pier column structures in ice-plagued area under highly seismic action

地震作用下冰水域桥墩受到动水压力与动冰荷载的的双重影响。基于Morison动水理论和Croteau动冰力模型,提出一种适用于冰水域桥墩动力时程反应分析的简便计算模型,通过振动台试验验证了其有效性,并分析了海冰质量和水深对冰海域桥墩动力响应的影响。结果表明,强震作用下有冰时墩底最大曲率比无冰时最大增加8.93倍,桥墩被自由冰包围时,墩底截面出现最大曲率时对应的海冰质量随着水深的增加而变大;随着冰质量的持续增大,墩身最大位移易超越极限位移,造成桥梁垮塌,在桥梁设计中应重点考虑。

The bridge piers located in the ice-plagued area are influenced by hydrodynamic pressure and dynamic ice-load under seismic action. Based on the Morison hydrodynamic theory and Croteau dynamic ice model, a simple calculating model for the time-history analysis subject to seismic effect for pier column structures in the ice-plagued area has been proposed; and its effectiveness has been verified with the shaking table test; the effect of ice mass and water depth on pier column has been analyzed as well. The results show that the maximum curvature at the bottom of pier with ice increased by 8.93 times than the case without ice. The ice mass corresponding to the maximum curvature of the cross-section at bottom of pier increased with the water depth. The maximum displacement of pier can exceed the limiting displacement easily with the increase of ice mass, which leads to a sudden collapse of bridges, and should been taken a key consideration in the aseismatic design of bridge.