地震作用下海冰与桥墩的间距对桥墩动力响应的影响研究

位于冰水海域的桥墩，在波浪力作用下，桥墩结构与周围海冰往往出现间隙，地震作用下海冰与结构的动力相互作用呈现复杂多样化。本文在弹性力学中的弹性波传播理论及结构动力学的基础上，考虑不同的海冰与桥墩间距，建立了地震作用下桥墩、冰与水体的流固耦合动力方程。并以一矩形桥墩为研究对象，研究了地震作用下，海冰与桥墩的间距对矩形桥墩结构的动力响应及动水压力的影响。研究表明：地震作用下，海冰与桥墩间距对桥墩顶部的最大位移和最大加速度响应的影响不显著，但是对桥墩侧面动水压力和墩底内力影响较大；当海冰与桥墩存在间距且小于1倍结构尺寸时，墩底的弯矩和剪力达到最大值。

THE EFFECT OF DISTANCE BETWEEN SEA ICE AND PIER ON DYNAMIC RESPONSES OF PIER STRUCTURES SUBJECT TO EARTHQUAKE

In icy waters, there are always distances between sea ice and structures due to the wave forces, and the seismic dynamic interaction of sea ice and structures is complicated. On the basis of elastic wave propagation theory and structural dynamics, the paper establishes the fluid-structure coupling dynamic equations of sea ice, water and piers with different distances between sea ice and structures. This paper takes a rectangular pier as an object of study, analyzes the effects of distance between sea ice and the pier on the seismic dynamic responses of the rectangular pier and hydrodynamic pressure. The results show that the distance between sea ice and the pier has little effect on the displacement responses and acceleration responses of the top pier under earthquake, but greatly influence the hydrodynamic pressures and inner forces of the bottom pier. The flexural moments and shear forces achieve the maximum when the distance between sea ice and pier exists and is less than the structure size.