双轴加载下变轴力大尺寸钢筋混凝土柱抗震性能试验研究  

Experimental study on seismic behavior of large size reinforced concrete columns under biaxial loading and variable axial loads

作　　者：郭玉荣[1,2] 梁康殷 吕聪 GUO Yurong;LIANG Kangyin;LV Cong(College of Civil Engineering,Hunan University,Changsha 410082,China;Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082

出　　处：《建筑结构学报》2024年第5期155-163,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51878259)。

摘　　要：为研究双轴加载与轴力变化对大尺寸钢筋混凝土(RC)柱抗震性能的影响,开展了4根截面尺寸600 mm×600 mm、高度3.6 m的钢筋混凝土柱拟静力试验。水平加载包括沿柱截面主轴方向的单轴加载和沿截面对角线方向的模拟双轴加载,变轴力的竖向加载频率为水平位移加载频率的3倍。针对承载力、位移延性、刚度退化及耗能能力等指标进行了大尺寸RC柱抗震性能分析。结果表明:与水平单轴加载相比,水平双轴加载会增强柱的耗能能力,但是柱刚度退化加快,延性降低;变轴力加载柱和定轴力加载柱的最终破坏形式相同,但是轴力变化对柱的破坏程度有显著影响,高轴压比会抑制柱身裂缝的发展;与定轴力柱相比,变轴力作用下柱顶水平荷载-位移滞回曲线不对称,水平加载对应轴力大的一侧,峰值荷载有所提高,耗能能力增强,但延性下降,刚度退化更快;同时承受双轴加载和变轴力的柱,滞回曲线的“捏拢”现象会更加明显。To study the effects of biaxial loading and variable axial load on the seismic performance of large size reinforced concrete(RC)columns,quasi-static cyclic loading tests of four columns with dimensions of 600mm×600mm in plan and 3.6m in hight were carried out.The lateral loads include two loading patterns:unidirectional loading along the main axis and simulated bi-directional loading along the diagonal axis of the column section.The axial loading frequency was three times of the horizontal displacement loading.The seismic performance of the large size RC column specimens was discussed in terms of column’s capacity,displacement ductility,stiffness degradation,and energy dissipation.The experimental results indicate that energy dissipation capacity of the columns can be enhanced under bi-directional horizontal loading when compared with unidirectional horizontal loading,but leading to faster stiffness degradation and lower ductility.The columns with and without axial loading variation shear the same failure mode,but the severity of damage is significantly affected by axial loading variation and the cracking of columns is restrained by larger axial compression ratio.When compared to columns under constant axial load,axial loading variation leads to an asymmetric lateral load-displacement hysteretic curve,in which the peak load and energy dissipation are increased on the side subjected to larger axial load,but with lower ductility and faster stiffness degradation.The pinching effect of the hysteretic curve is more severe when the columns are under bi-directional loading combined with variable axial load.

关 键 词：钢筋混凝土柱 拟静力试验 双轴加载 变轴力 抗震性能 

分 类 号：TU375.3[建筑科学—结构工程] TU317