主余震作用下钢管混凝土箱形叠合墩拟动力试验  

Pseudo-dynamic Test of CFST Reinforced Concrete Piers with Hollow Box Sections Under Action of Mainshock and Aftershocks

作　　者：袁辉辉[1,2] 程军 吴庆雄[1,3] 佘智敏 YUAN Hui-hui;CHENG Jun;WU Qing-xiong;SHE Zhi-min(College of Civil Engineering,Fuzhou University,Fuzhou 350116,Fujian,China;Key Laboratory of Civil Engineering-Fujian Province University,Fuzhou University,Fuzhou 350116,Fujian,China;Fujian Provincial Key Laboratory on Multi-disasters Prevention and Mitigation in Civil Engineering,Fuzhou University,Fuzhou 350116,Fujian,China;College of Civil Engineering,Putian University,Putian 351100,Fujian,China)

机构地区：[1]福州大学土木工程学院,福建福州350116 [2]福州大学工程结构福建省高校重点实验室,福建福州350116 [3]福州大学福建省土木工程多灾害防治重点实验室,福建福州350116 [4]莆田学院土木工程学院,福建莆田351100

出　　处：《中国公路学报》2023年第7期180-192,共13页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51978169);国家重点研发计划项目(2017YFE0130300);福建省高校产学合作项目(2021H6021);莆田学院引进人才科研启动费项目(2022057)。

摘　　要：为了研究地震动特性、地震动强度和主余震作用下新型组合结构钢管混凝土箱形叠合墩(简称CFSTRC墩)的抗震性能,进行了2个CFSTRC墩1∶11.6缩尺模型的拟动力试验。研究结果表明:在峰值加速度(PGA)均按比例调幅为0.05g的10条国内外强地震动作用下,CFSTRC墩试件处于弹性工作状态,其中日本阪神大地震JRT波作用下的最大位移响应是平均值的1.68倍。在9度罕遇主震(PGA约为0.7g)作用下,试件S1进入强度劣化阶段,而试件S2仍处于弹塑性变形阶段;2个试件的破坏形态均表现为沿加载方向腹板的剪切斜裂缝、垂直加载方向腹板的水平向裂缝,同时伴随着柱肢底部钢管局部屈曲引起的外包混凝土竖向裂缝,导致试件刚度显著降低。随着余震PGA逐级增大,主震中已损伤试件的墩顶最大位移响应呈线性增大,累积滞回耗能呈非线性增长;在与主震地震强度相当的余震作用下,2个试件的累积损伤进一步加剧,水平承载力平均下降约17%,累积滞回耗能减少约16%,墩顶最大位移响应增加约3%。最后,采用基于结构最大变形与累积滞回耗能线性组合的地震损伤指标可比较准确地评估CFSTRC墩在主余震作用下的抗震性能。A pseudo-dynamic test of two 1/11.6-scaled concrete-filled steel tube(CFST)-reinforced concrete(CFSTRC)column with hollow box sections was performed to study the influence of the ground motion characteristics,ground motion intensity,mainshocks and aftershocks on the seismic performance of the CFSTRC columns.The results show that the CFSTRC column specimens completely function in the elastic state under the action of 10 strong earthquakes with the peak ground acceleration(PGA)modulated proportionally to 0.05g,and the maximum displacement response under the action of the JRT ground motions of the Great Hanshin Earthquake in Japan was 1.68 times the average value.Under the action of the 9-degree rare mainshocks(PGA≈0.7g),specimen S1 entered the strength deterioration stage,whereas specimen S2 was still in the elastoplastic deformation stage.The failure modes of the two specimens were both shear diagonal cracks in the web along the loading direction,horizontal cracks in the web perpendicular to the loading direction,and the vertical cracks in the outer concrete caused by the local buckling of the steel tube at the column bottom,resulting in a significant decrease in the structural stiffness.As the PGA of the aftershock increased step by step,the maximum displacement response of the damaged specimen in the mainshock increased linearly,and the cumulative hysteretic energy dissipation increased nonlinearly.Under the action of aftershocks with the same PGA as the mainshocks,the cumulative damage to the two specimens was further exacerbated,the horizontal strength decreased by about 17%on average,the cumulative hysteretic energy dissipation decreased by about 16%,and the maximum displacement response on the column top increased by about 3%.Finally,the seismic damage index based on the linear combination of maximum structural deformation and cumulative hysteretic energy dissipation can be used to accurately evaluate the seismic performance of CFSTRC columns under the action of mainshock and aftershocks.

关 键 词：桥梁工程 钢管混凝土箱形叠合墩 拟动力试验 抗震性能 主余震 地震响应 

分 类 号：U443.22[建筑科学—桥梁与隧道工程]