He Haifang, Zhou Yulong, Cheng Shoushan, Liu Hongyi
National Engineering Laboratory of Bridge Safety and Technology (Beijing), Research Institute of Highway Ministry of Transport, Beijing 100088, China.
Materials (Basel). 2023 Sep 30;16(19):6515. doi: 10.3390/ma16196515.
Rocking piers using ultra-high-performance concrete (UHPC) have high damage-control capacity and self-centering characteristics that can limit the post-earthquake recovery time of bridges. To study the hysteretic behavior of UHPC rocking piers, a lumped plasticity model is proposed that comprises two parallel rotational springs and which can accurately calculate their force-displacement hysteretic behavior. Three states of the rocking piers, decompression, yield, and large deformation, are considered in this study. The model is verified based on existing experimental results, and the hysteretic characteristics of the UHPC rocking piers, such as strength, stiffness, and energy dissipation, are further analyzed. The research results show that the lumped plasticity analysis model proposed in this study can predict the force-displacement hysteretic behavior of the rocking piers accurately. Moreover, the hysteretic performance of the UHPC rocking piers is better than that of rocking piers using normal-strength concrete. An increase in the energy dissipation reinforcement ratio, pre-stressed tendon ratio, and initial pre-stress improves the lateral stiffness and strength of the UHPC rocking piers. However, the increase in the pre-stressed tendon ratio and initial pre-stress reduces their energy-dissipation capacity.
采用超高性能混凝土（UHPC）的摇摆桥墩具有高损伤控制能力和自复位特性，能够缩短桥梁震后恢复时间。为研究UHPC摇摆桥墩的滞回性能，提出了一种集总塑性模型，该模型由两个并联的转动弹簧组成，能够精确计算其力-位移滞回性能。本研究考虑了摇摆桥墩的三种状态，即解压、屈服和大变形。基于现有试验结果对该模型进行了验证，并进一步分析了UHPC摇摆桥墩的滞回特性，如强度、刚度和耗能等。研究结果表明，本研究提出的集总塑性分析模型能够准确预测摇摆桥墩的力-位移滞回性能。此外，UHPC摇摆桥墩的滞回性能优于普通强度混凝土摇摆桥墩。耗能增强比、预应力筋比率和初始预应力的增加提高了UHPC摇摆桥墩的横向刚度和强度。然而，预应力筋比率和初始预应力的增加降低了它们的耗能能力。
