自复位预制节段拼装中空夹层钢管混凝土桥墩地震易损性分析

Seismic Fragility Analysis of Self-centering Precast Segmental Concrete-filled Double Skin Steel Tubular Piers

为评估自复位预制节段拼装中空夹层钢管混凝土(Concrete-filled Double Skin Steel Tubular,CFDST)桥墩在地震动作用下的易损性,本研究基于现有的低周反复荷载试验数据,采用有限元分析方法,选用墩顶水平位移角和残余位移角2个指标作为评估标准进行定量分析。针对3种不同类型地震动(远场、近场无脉冲和近场有脉冲),分别建立了关于水平位移角和残余位移角2个指标的易损性曲线,并分析了不同损伤指标和地震动类型对其地震易损性的影响。研究结果表明,在自复位预制节段拼装CFDST桥墩地震易损性分析中,仅采用水平位移角作为损伤指标是安全可靠的;相比远场地震动和近场无脉冲型地震动而言,近场脉冲型地震动对自复位预制节段拼装CFDST桥墩的变形和自复位有显著影响。

This paper evaluates the seismic vulnerability of self-centering precast segmental concrete-filled double skin steel tubular(CFDST)piers by quantitatively assessing their seismic performance under three types of ground motions:far-field,near-field without pulse,and near-field pulse-like motions,based on existing quasi-static tests.Using finite element analysis,vulnerability curves for the self-centering precast segmental CFDST piers are established based on two damage indices:the horizontal displacement angle and the residual displacement angle.The study analyzes the effects of different damage indices and ground motion types on the vulnerability curves of the self-centering precast segmental CFDST piers.The results indicate that utilizing only the horizontal displacement angle as the damage index is both safe and reliable for the seismic vulnerability analysis of these piers.Additionally,it was found that near-field pulse-like ground motions significantly affect the deformation and self-centering behavior of the self-centering precast segmental CFDST piers compared to far-field and near-field non-pulse-like ground motions.