【摘要】 研究固结冰包围的桥墩地震动力响应简化计算模型,并考虑不同水深、不同地震类型和行波效应条件,分析地震动多点输入下固结冰对桥墩结构地震反应的影响。结果表明:桥墩被固结冰包围时地震动一致激励下桥墩的地震反应显著大于无冰时,墩底截面最大曲率、桥墩顶部位移比无冰时增大,达到50%以上;墩底截面弯矩-曲率滞回曲线呈倒"S"形更显著,桥墩的变形和耗能能力显著下降。另外,地震动的行波效应对桥墩的地震反应有较大的影响,但随着视波速的变化并无明显的规律,不同类型的地震动作用下桥墩的最大地震反应出现在不同的视波速时。在设计固结冰包围的桥墩时应考虑地震动的多点输入,并根据固结冰的大小及地震动的类型考虑地震动行波效应。更多还原

【Abstract】 Based on the calculation models of a pier surrounded by consolidated sea ice under multiple-support excitation, the effects of consolidated ice on nonlinear seismic responses of the pier were analyzed considering the depth of water, the different types of earthquakes and traveling wave effect. The results show that comparing to without ice, the seismic responses of the pier surrounded by consolidated ice are more remarkable, and the maximum curvatures and displacements of the pier increase more than 50%. Further, when the pier is surrounded by consolidated ice, the M-Φ hysteretic curves of the cross-section of the pier subject to earthquakes present downfallen ‘S’ form significantly, which means that the deformability and energy dissipation capability of the pier drop remarkably. Besides, the wave-traveling wave effect influences the seismic response greatly, but there is no distinct rule of responses change accompanying the apparent wave velocity varying. Under different types of earthquakes, the maximum seismic responses occur under different apparent wave velocities. So when design a bridge pier surrounded by consolidated sea ice, the multiple-support excitation should be considered and taking the size of consolidated sea ice and types of ea rthquakes to consider the traveling wave effect.更多还原