后张预应力节段拼装CFST桥墩抗侧力学行为试验

发布时间：2018-12-30 10:49

【摘要】：为发展绿色、高效及可恢复功能的新型预制装配式桥梁结构体系,提出将钢管混凝土(CFST)应用于后张预应力节段预制拼装桥墩的结构形式。介绍了后张预应力节段拼装CFST桥墩关键构造、受力状态及力学行为特征,建立其关键部件设计方法。设计并加工制作了试验模型试件,开展了轴心后张预应力节段拼装CFST桥墩侧向往复加载拟静力试验,揭示了其水平往复加载过程中的滞回行为、骨架曲线、预应力损失、耗能能力、节段间接缝张口、节段间接缝滑移及塑性铰发展等非线性力学行为。研究结果表明:该后张预应力节段拼装CFST桥墩具有较高的抗侧能力和良好的自复位性能,侧向承载能力失效时残余偏移率为0.2%;水平往复位移将会造成较大的预应力损失,失效时即水平最大位移偏移率5.8%时,预应力损失约15%;节段预制拼装CFST墩柱出现双塑性铰效应,底部接缝开口较大,其上相邻接缝处开口量显著减小;试验后接缝处没有出现显著水平移位或错动现象,预制节段墩身没有出现明显外观损伤,底部接缝处应力集中区域钢管内少量混凝土破碎,导致钢管局部屈服;无附加耗能装置的后张预应力节段拼装桥墩耗能能力较差,建议在接缝开口处附设耗能装置。研究成果可为自复位预制拼装CFST桥墩设计和性能优化提供重要参考。
[Abstract]:In order to develop a new type of prefabricated bridge structure system with green, high efficiency and recoverable function, a new type of prefabricated pier with concrete filled steel tube (CFST) is proposed. This paper introduces the key structure, stress state and mechanical behavior characteristics of CFST pier assembled with post-tensioned prestressing section, and establishes the design method of its key components. The test model specimen was designed and manufactured, and the pseudostatic test of lateral reciprocating loading of CFST pier was carried out, which revealed the hysteretic behavior, skeleton curve and prestress loss during horizontal reciprocating loading. Nonlinear mechanical behaviors such as energy dissipation capacity, joint opening between segments, slippage of joints between segments and plastic hinge development. The results show that the post-tensioned CFST pier has high lateral resistance and good self-reset performance, and the residual deviation rate is 0.2 when the lateral bearing capacity fails; Horizontal reciprocating displacement will cause a large loss of prestress. When failure occurs, when the maximum displacement deviation rate of horizontal displacement is 5.8, the loss of prestressing force is about 15. There is a double plastic hinge effect on the prefabricated CFST pier column, the opening of the bottom joint is larger, and the amount of the opening at the upper adjacent joint decreases significantly. After testing, there is no obvious horizontal displacement or dislocation at the joint, no obvious damage to the pier body of the precast segment, and a small amount of concrete in the steel tube in the stress concentration area at the bottom joint, which leads to the local yield of the steel tube. The energy dissipation capacity of the post-tensioned prestressed segment piers without additional energy dissipation devices is poor. It is suggested that energy dissipation devices should be installed at the joint opening. The research results can provide important reference for self-reset prefabricated CFST pier design and performance optimization.
【作者单位】：北京工业大学城市与工程安全减灾教育部重点实验室;招商局重庆交通科研设计院有限公司桥梁工程结构动力学国家重点实验室;北京市政路桥管理养护集团有限公司;
【基金】：国家自然科学基金项目(51378033,51578030) 北京市自然科学基金项目(8162007)
【分类号】：U446.1

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