可更换低屈服波形钢腹板连梁-组合桥墩耗能机理与抗震性能

为提高桥梁结构震后功能可恢复性，提出一种可更换低屈服波形钢腹板连梁-组合桥墩结构。结合模型试验、数值模拟和理论分析，从材料、构件、结构三个层面开展其耗能机理与抗震性能研究：首先，建立考虑应变幅值依赖性、加载历程相关性的低屈服钢材滞回本构模型；其次，揭示低屈服波形钢腹板连梁反复荷载作用下的耗能机理，提出可准确描其恢复力-变形关系的动力本构模型；再次，探究波形钢腹板连梁与组合墩柱之间动力相互作用，明确波形钢腹板连梁-组合桥墩结构地震荷载作用下的破坏机理、耗能机制以及强度、刚度累积损伤过程；最终，建立综合考虑结构损伤、功能可恢复指标的可更换低屈服波形钢腹板连梁-组合桥墩的抗震性能评价体系，并给出相应的抗震设计建议。研究成果将有益于完善可更换低屈服波形钢腹板连梁-组合桥墩的功能可恢复抗震设计，促进其工程应用。

In order to improve the post-earthquake resilience of bridge structure, a composite pier connected by replaceable low yield point steel coupling beams with corrugated web is proposed. Combining the methods of model tests, numerical simulations and theoretical analysis, a series of studies will be conducted on the energy dissipation mechanism and seismic performance of proposed composite pier from three levels including materials, components, and structures. First, the hysteretic constitutive model for low yield point steel considering the strain amplitude dependence and loading history correlation by cyclic loading will be established. Next, the energy dissipation mechanism of low yield point steel coupling beams with corrugated web under repeated loads is revealed, and a dynamic constitutive model will be proposed which can accurately describe its restoring force-deformation relation. Then, the dynamic interaction between coupling beams and composite pier column will be explored. In addition, the failure mode, energy dissipation mechanism, cumulative damage process of the strength and stiffness for proposed composite pier structure under seismic loading will be detected. Finally, a seismic performance evaluation system for proposed composite pier structure is established, which takes into account structural damage index and functional recovery index, and the corresponding seismic design suggestions will be provided. These research results will be beneficial to improve the resilience seismic design of such composite pier connected by replaceable low yield point steel coupling beams with corrugated web and promote the engineering application of proposed composite pier structures.