桩-土作用对大跨径斜拉桥非一致激励响应的影响研究

Influences of pile-soil interaction on long-span cable-stayed bridge without auxiliary pier under non-uniform excitation

以陕西某待建无辅助墩大跨径叠合梁斜拉桥为例,建立Midas/Civil模型,计算了该桥的动力特性,以有无桩-土相互作用为变量对该桥梁在非一致地震激励下的响应进行研究分析。结果表明:考虑桩-土相互作用的桥梁的自振周期增大,振型特征不变,桥梁关键部位的位移响应减小,主梁内力响应减小,而桥塔底部剪力和弯矩显著增大。

In this paper, a midas/Civil model is established for a long span composite girder cable-stayedbridge with no auxiliary pier in Shaanxi Province, and the dynamic characteristics of the bridge are calculated,and the response of the bridge under non uniform earthquake excitation is studied and analyzed with the help ofpile-soil interaction as variable. The results show that the self vibration period of the bridge with pile-soil interactionis increased, the modal characteristics are unchanged, the displacement response of the key parts of thebridge is reduced, the main beam internal force response is reduced, and the shear and bending moments inthe bottom of the bridge tower are significantly increased.