钢管混凝土组合桥墩和钢筋混凝土桥墩抗震性能对比研究

钢管混凝土组合桥墩(以下简称组合桥墩)是一种在传统钢筋混凝土桥墩内设置核心钢管的新型墩柱。基于2个组合桥墩和2个钢筋混凝土桥墩试件的拟静力试验,讨论了两类桥墩的抗震性能差异,分析了内置核心钢管对墩柱水平承载力、变形能力、滞回耗能和残余位移的影响。研究结果表明:剪跨比λ=3.0和λ=2.0的桥墩试件分别发生弯曲破坏和弯剪破坏;在荷载-位移滞回曲线方面组合桥墩试件表现出较为饱满的曲线特性;在强度衰减和刚度退化方面,组合桥墩试件退化速度较慢,即使位移达到限值时,仍能保持其稳定性;内置核心钢管对墩身初始水平刚度影响甚微,但能提高试件的水平承载力、变形和耗能能力,并能有效减小卸载后的墩顶残余位移。研究成果可为组合桥墩的工程应用提供试验基础。

Comparative Study on Seismic Behavior of Steel Tube Reinforced Concrete Bridge Columns and Reinforced Concrete Bridge Columns

Steel tube reinforced concrete bridge column is a new type of bridge column,which consists of a reinforced concrete column and a pre-embedded core steel tube.In this paper,two steel tube reinforced concrete bridge column specimens and two reinforced concrete bridge column specimens are tested under low cyclic reversed loading.The difference on the seismic behavior between two types of bridge columns is discussed.Besides,the effects of built-in core steel tube on the lateral load capacity,deformability,hysteretic energy dissipation,and residual displacement of bridge columns are evaluated.Test results indicate that the column specimens with shear span ratios ofλ=3.0 andλ=2.0 subjected to flexural failure and flexural-shear failure respectively.The steel tube reinforced concrete bridge columns show plump and stable load-displacement hysteretic curves,with a gentle degradation in strength and stiffness until column failure occurs.It is also found that imbedding a core steel tube into an reinforced concrete column barely increased the column initial lateral stiffness,whereas the lateral load capacity,deformability and energy dissipation are improved,and the residual displacements are reduced.This research could provide experimental reference for engineering applications of steel tube reinforced concrete bridge column.