Conventional reinforced concrete piers are vulnerable to severe compressive damage under strong earthquake conditions and are difficult to quickly rehabilitate. This paper develops a new type of composite pier, consisting of ultra-high-performance concrete (UHPC) and reinforced concrete (RC). This UHPC-RC composite pier uses a UHPC cover outside of an RC core to achieve a high load-carrying capacity and mitigate compressive damage. An experiment is performed to evaluate the performance of the UHPC-RC composite pier under cyclic deformation. The crack development, ultimate failure modes, and load-carrying capacities of the pier are observed. Because of the extraordinary compressive strength of UHPC, the composite pier suffers little compressive damage under large lateral deformations. The composite pier fails as a result of fracturing of the reinforcement. A numerical model is developed to reproduce the cyclic behavior of the composite pier. On the basis of the verified numerical model, a parametric analysis is used to investigate the influence of the thickness of the UHPC cover and the axial load ratio. Finally, an approach is recommended for designing composite piers.

传统的钢筋混凝土桥墩在强震条件下容易受到严重的压缩破坏，难以快速修复。本文开发了一种新型复合桥墩，由超高性能混凝土（UHPC）和钢筋混凝土（RC）组成。该 UHPC-RC 复合桥墩在 RC 芯材外部使用 UHPC 盖板，以实现高承载能力并减轻压缩损坏。进行了一项实验，以评估 UHPC-RC 复合材料桥墩在循环变形下的性能。观察了桥墩的裂缝发展、最终破坏模式和承载能力。由于UHPC非凡的抗压强度，复合材料桥墩在大侧向变形下几乎没有受到压缩破坏。复合桥墩因钢筋断裂而失效。开发了一个数值模型来重现复合桥墩的循环行为。在经过验证的数值模型的基础上，采用参数化分析研究了UHPC盖板厚度和轴压比的影响。最后，推荐了一种设计复合桥墩的方法。