陡横坡地形下桩顶系梁对多柱式墩桥梁抗震性能的影响分析

Analysis of the Influence of the Tie Beam at the Top of Pile on the Seismic Performance of the Multi Column Pier Bridge under the Steep Cross Slope Terrain

我国西南地区地形多高山深谷,有必要探讨在陡横坡地形下,多柱墩桩顶系梁布置对桥梁抗震性能的影响。以某铁路桥为实例,通过Midas/Civil有限元软件建立空间三维模型,设置多种工况,提取与对比利用反应谱法计算得出的E1地震下内力与位移,与利用折减刚度的反应谱法计算得出的E2地震下的位移。分析结果表明:在陡横坡地形下,依据传统桩顶系梁的布置方式并未最优,以本文工况5设置的桥墩内力分布与位移较优,也应注意验算顺桥向中间墩墩底的抗剪强度。

In Southwest China,there are many high mountains and deep valleys,and earthquakes are frequent.Under the steep cross slope terrain,how to set up the pile top tie beam for the multi column pier has become an urgent problem to be solved.At present,scholars and designers at home and abroad have not fully studied this problem.In this paper,taking some railway bridge as an example,the spatial three-dimensional model is established by Midas/Civil finite element software and it is used to analyze the seismic behavior of the bridge under the action of E1 and E2 earthquake.The results show that the internal force distribution and displacement of the pier are better under the mode of working condition 5,but the shear force at the bottom of the intermediate pier will also increase.In the actual setting,attention should be paid to checking the shear strength of the pier bottom along the bridge direction.