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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。
In order to develop a new type of prefabricated bridge structural system with green, high efficiency and recoverability, the CFST structure is proposed for prefabricated piers of post-tensioned prestressed sections. The key structure, the state of stress and the mechanical behavior of the CFST piers assembled with post-tensioned prestressed sections are introduced, and the key components design method is established. The test model specimens were designed and machined, and the quasi-static tests of the CFST pier subjected to axial reciprocating prestressing were carried out. The hysteretic behavior of the CFST piers was revealed, including the hysteretic behavior, the skeleton curve, the prestressing force Loss, energy dissipation ability, inter-section joint slot, inter-section joint slippage and the development of plastic hinge nonlinear mechanical behavior. The results show that the post-tensioned prestressed CFST bridge piers have high lateral resistance and good self-resetting performance, and the residual displacement rate is 0.2% when the lateral bearing capacity fails. The horizontal reciprocating displacement will cause larger Of the prestress loss, the failure of the level of the maximum displacement displacement rate of 5.8%, the prestress loss of about 15%; section prefabricated CFST piers appear double plastic hinge effect, the bottom of the seam opening larger, adjacent to the adjacent There was no obvious horizontal displacement or staggering phenomenon in the seams after the test, no obvious appearance damage occurred in the prefabricated section pier body, and a small amount of concrete in the steel pipe in the stress concentration area at the bottom seams was broken, resulting in the failure of the steel pipe Local yield; Post-tensioned prestressed segment piers with no additional energy dissipation devices have poor energy dissipation capacity. It is suggested that energy dissipation devices be attached to the joint openings. The research results provide an important reference for the design and performance optimization of prefabricated CFST piers.