摘要
设计制作了11个钢筋混凝土箱型截面桥墩缩尺模型,对其进行了粘钢加固后的双向拟静力试验,分析了加固桥墩的荷载-位移滞回曲线、骨架曲线、延性能力、刚度退化和耗能能力等.结果表明,加固墩柱均发生以弯曲破坏为主的延性破坏,破坏塑性铰由未加固时的墩底上移至加固钢板位置的上边缘,加固后墩柱各项抗震性能良好,表明粘钢加固损伤桥墩是一种有效的抗震加固方式.墩柱强轴方向的滞回环饱满,承载力和刚度较大;弱轴方向的滞回环捏缩效应显著,耗能能力较强.初始损伤程度仅对粘钢加固墩柱的刚度退化及耗能能力具有一定影响.随着轴压比的增大,加固试件的承载力变大,极限变形能力降低,延性能力和耗能能力均增强.而随着长细比的减小,加固试件的承载力变大,极限变形能力降低,刚度退化情况严重.
11 scaled models of reinforced concrete bridge piers with hollowbox-section were designed and fabricated in the lab.Bi-directional quasi-static tests for these scaled pier models strengthened with adhering steel plates were carried out.Several seismic performance indicators,such as load-displacement hysteretic and skeleton curves,ductility,degradation of rigidity,and energy dissipation were investigated.The experimental results showthat all the strengthened piers present typical flexural failure modes,and plastic hinge appears in the superior margin of steel plates in stead of in the bottom for piers without strengthening.The improvement of anti-seismic properties exhibits that it was an effective method to change the plastic hinge position by adhering steel plates.The load capacity and the lateral rigid along the strong axis direction are greater,while the energy dissipation along the weak axis direction is stronger.The hysteretic curves of the weak axis exhibit notable pinch effects.The initial damage only has small effect on the degradation of rigidity and energy dissipation of the strengthening piers.Meanwhile,the changes of axial compression ratio and slenderness ratio have a great impact on the seismic performance.With the increase of the axial compression ratio,the carrying capacity,the ductility performance and energy dissipation of models increase,but the ultimate displacement decreases.With the decrease of the slenderness ratio,the carrying capacity of piers strengthened with adhering steel plates increases;however the ultimate deformation capacity decreases,while the degradation of rigidity becomes more serious.
引文
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