外置可更换耗能装置的节段拼装CFST桥墩抗震性能分析

为顺应桥墩震后使用功能快速修复的新要求，提高预制拼装桥墩在中、高烈度地震区的适用性能，提出了一种外置可更换耗能装置的节段拼装钢管混凝土（CFST）桥墩. 基于ABAQUS有限元分析软件建立了三节段后张预应力预制拼装CFST桥墩分析模型，对外置3种不同控制参数（截面贡献率、耗能钢棒长细比及其布置方式）耗能装置的桥墩模型在往复加载作用下的抗震性能进行了分析. 研究结果表明:外置耗能装置的节段拼装CFST桥墩墩身损伤可控，能够通过更换耗能装置等措施实现震后的快速修复；与未设置耗能装置的桥墩相比，该类桥墩的侧向承载力、初始刚度和耗能能力分别提升了11%~88%、2.86%~6.87%和2.3倍~12.9倍；为保证震后修复的可行性，建议耗能装置的截面贡献率宜低于1.9%；中部接缝处设置的耗能钢棒直径过小将阻碍墩底处耗能钢棒充分发挥耗能作用，耗能装置沿墩高方向布置的折减系数大于0.5；耗能钢棒长细比的改变会影响墩柱的抗侧强度和延性，长细比减小，桥墩耗能能力逐渐提升，但残余位移也逐渐增大，建议耗能钢棒长细比的取值宜大于4.5. 

Seismic Performance of Precast Segmental CFST Bridge Piers with External Replaceable Energy Dissipation Devices

To meet the new requirements of bridge piers for rapid repair after earthquake and improve the suitability of precast segmental bridge piers in medium and high intensity areas, a precast segmental concrete filled steel tube (CFST) bridge pier with external replaceable energy dissipation devices was proposed. Based on the ABAQUS software, the analysis models of the post-tensioned prestressing precast segmental CFST piers with three segments were established. The seismic performance of the precast segmental CFST piers with the energy dissipation devices of three different control parameters (section contribution rate, slenderness ratio and arrangement) was analyzed under cyclic loading. The results show that the precast segmental CFST piers can be rapidly repaired by replacing energy dissipation devices and other measures due to the damage level of piers can be controlled by using external energy dissipation devices. Compared with the pier without energy dissipation device, the lateral strength, initial stiffness and energy dissipation capacity of the precast segmental CFST piers with external energy dissipation devices are increased 11%?88%, 2.86%?6.87% and 2.3 times?12.9 times, respectively. Meanwhile, to ensure the feasibility of repair after an earthquake, it is suggested that the section contribution rate of the external energy dissipation devices should not exceed 1.9%. Due to the small diameter of the energy dissipation bar on the middle joint which will cause the energy dissipation bar at pier bottom to not be fully utilized, it is suggested that the reduction factor of the energy dissipation devices along the pier height should not be less than 0.5. The change of slenderness ratio of energy dissipation bars has an effect on the lateral strength and ductility of the piers. With the decrease of the slenderness ratio, the energy dissipation capacity increases but the residual displacement of the piers also increases gradually. It is suggested that the slenderness ratio of energy dissipation bars should be greater than 4.5.