锈蚀对外包钢板加固钢筋混凝土桥墩的影响

Corrosion effect of reinforced concrete bridge piers wrapped by steel plates

建立二维弹塑性有限元模型研究外包钢板加固钢筋混凝土桥墩在底部附近钢板发生锈蚀情况下的极限承载力变化规律。首先通过与试验结果的比较,验证本文所采用的有限元分析方法的准确性与有效性。然后以实际桥墩P2柱的底部附近钢板锈蚀率、锈蚀模式为变化参数,研究不同翼缘和腹板锈蚀率下桥墩的极限承载力、混凝土裂缝开展范围、钢板的屈服区域特点等。研究结果表明,桥墩的极限承载力随底部附近钢板的锈蚀率增大而减小,均匀锈蚀模式下的钢板锈蚀率与桥墩极限承载力之间呈现明显的线性相关关系,而腹板的不均匀锈蚀模式引起的极限承载力劣化远大于均匀锈蚀模式。

Two- dimensional elasto- plastic finite element formulation is employed to investigate the load - carrying capacity of reinforced concrete piers wrapped by steel plates which are corroded at the pier base. By comparing with experimental results, the employed finite element analysis method is verified to be accurate and effective. After that, a series of parametric studies are carried out to investigate the effect of corrosion rate and corrosion mode of steel plates near the base of in - service pier P2 on load - carrying capacity, concrete cracking scope, yield range of wrapped steel plates. It is concluded that the load - carrying capacity decreases with the increase of steel plates＇ corrosion rate. There is an obvious linear relationship between the load - carrying capacity and the corrosion rate in the case of even corrosion mode. The deterioration of load - carrying capacity resulted from the web plates＇ uneven corrosion mode is more serious than that under even corrosion mode.