【摘要】 针对预制-拼装结构的施工优势、摇摆-自复位结构的抗震优点及角钢的特性,提出含角钢的摇摆-自复位双柱墩和含角钢及耗能钢筋的摇摆-自复位双柱墩。基于OpenSees数值平台建立了这2种双柱墩的精细化数值分析模型,分别结合角钢的循环拉压试验以及摇摆-自复位双柱墩的拟静力试验结果验证了模型的准确性。在此基础上,通过拟静力和动力时程分析,并通过与普通钢筋混凝土双柱墩的对比,揭示了新型摇摆-自复位双柱墩的抗震能力。结果表明:与普通双柱墩相比,摇摆-自复位双柱墩侧向初始刚度减少,自振周期增大;在0.4g近断层地震动下预应力筋始终处于弹性阶段且桥墩震后几乎无残余位移,便于双柱墩的震后功能恢复;外置角钢在0.1g近断层地震动下屈服并开始耗能,在0.4g近断层地震动下可能发生拉断破坏;在摇摆-自复位双柱墩接缝处配制一定的耗能钢筋后(配筋率小于0.4%),可降低墩顶变形,减少预应力筋应力和外置角钢的变形,且摇摆-自复位双柱墩的震后残余位移未明显增加。更多还原

【Abstract】 In allusion to the construction advantage of the precast-assembly structure and good seismic behavior of the rocking self-centering structure,two innovative rocking self-centering double column bridge bents were proposed.One was designed with external angles and the other with external angles and energy dissipation bars.The detailed finite analysis models for both of the bents based on OpenSees platform were established,and the accuracy of the models was verified by comparing with cyclic tension and compression test results for angles and quasi-static test results for rocking self-centering double column bents.On this basis,the seismic behavior of the rocking self-centering bents were investigated by quasi-static and dynamic time-history analysis results of the bents,and the behavior of the rocking self-centering bents was comparedwith that of commonly used reinforced concrete bents.The results show that,compared with commonly used bents,both of the rocking self-centering bents show smaller initial lateral stiffness and larger natural vibration period.The prestressing tendon in the elastic stage shows negligible residual displacement under 0.4 g near-fault ground motions,which is beneficial for rehabilitation of the double column bridge bents.The external angles may yield and absorb seismic energy under 0.1 gnear-fault ground motions and will be fractured under 0.4 gnear-fault ground motions.When the rocking self-centering bents are designed with some energy dissipation bars with a reinforcement ratio less than 0.4%,the deformation of the bents,the prestressing stress of the tendons and the deformation of the angles will decrease,compared with the bents designed only with angles.And the energy dissipation bars induce a little increase for the residual displacement of the rocking self-centering double column bents.更多还原