柔性横系梁双柱墩的抗震行为分析

Seismic Behavior Analysis for Link Beam of Double-Column Bent

摘要:

基于Pushover分析方法，探索柔性横系梁对双柱式桥墩抗震行为的影响。采用弹塑性纤维单元，建立单柱墩、盖梁双柱墩和柔性横系梁双柱墩模型进行对比分析，研究横系梁刚度变化对桥墩破坏机理、墩顶位移能力、位移延性系数以及基础受力的影响。结果表明，随着横系梁刚度的增大，墩顶位移延性能力逐渐减小，位移延性系数逐渐增大，桥墩的承载能力逐渐增大，同时提供给基础水平推力能力增大。对于规则桥墩，柔性横系梁双柱墩的墩顶最大塑性位移比单柱墩略小，可按单柱墩位移延性能力计算公式计算其墩顶位移延性能力。

Abstract:

To explore what seismic behavior effects link beam will have on its double-column bent based on pushover analysis method. The elastic-plastic fiber surface element is applied to the construction of three respective models — single-column bent model, double-column bent model and link beam double-column bent model, to study the difference of failure mechanism of piers ,displacement ductility capacity on the top pier, displacement ductility factor and force acting on the foundation by changing the stiffness of link beam. The results of these analyses indicate that with the increasing stiffness of link beam, there will be a decreasing trend of displacement ductility capacity on the top pier, a gradual increase of displacement ductility factor and load-carrying capacity of piers, thus more lateral force capacity will be passed to the foundations. For the regular pier, the maximum plastic displacement on the top pier of the link beam of double-column is slightly smaller than that of single column bent .and its displacement ductility capacity can be calculated as that of single column bent.