罕遇地震下曲线钢-混凝土组合梁桥的墩柱扭转效应

为了研究曲线钢-混凝土组合梁桥在罕遇地震下的墩柱扭转效应,基于考虑扭转效应的钢管混凝土纤维梁模型,建立了曲线组合梁桥的杆系有限元分析模型。对不同输入方向的三条地震波作用下是否考虑墩柱扭转效应的纤维梁模型的计算结果进行了对比,包括墩顶位移、墩柱扭转角和墩柱内力等。在此基础上,对曲线组合梁桥在罕遇地震作用下的扭转效应的关键影响参数进行了分析。结果表明:采用考虑扭转效应的纤维梁模型分析曲线组合梁桥在地震作用下的受力反应,可有效的反映罕遇地震下曲线钢-混凝土组合梁桥的墩柱扭转效应。另外,曲率半径和墩高是影响曲线组合梁桥在纵向地震作用下墩柱扭转效应的主要因素。

TORSION EFFECT IN PIERS OF CURVED STEEL-CONCRETE COMPOSITE BRIDGES UNDER RARE EARTHQUAKE

In order to study the torsion effects in piers of steel-concrete composite girder bridges under rare earthquake conditions, a finite element model was established based on the fiber beam-column model for concrete filled steel tubes considering torsion effects. Three different earthquake waves were applied, and comparisons amongst the results with and without torsion effects were made in terms of displacement, torsion angle and internal force of the piers. Results with torsion effects were further analysed to address key influencing factors. It is shown that torsion effects in piers of curved steel-concrete composite girder bridges under rare earthquake conditions can be effectively considered using the proposed fiber beam-column model. Furthermore, it is noted the radius and the height of piers were the main influencing factors on the torsion effects of curved steel-concrete composite girder bridges subjected to longitudinal earthquake loads.