摘要
为研究压-弯-剪-扭复合作用下空腹式角钢骨架混凝土(OTSRC)柱的抗震性能,以扭弯比、轴压比、剪跨比、腹杆配箍率和保护层厚度为试验参数,完成了10根OTSRC柱的压-弯-剪-扭低周反复加载试验。观察OTSRC柱在复合受扭状态下的破坏特征,分析各参数对其滞回曲线、骨架曲线、延性、耗能、刚度退化等抗震指标的影响规律。结果表明:随扭弯比增大,OTSRC柱依次发生弯曲破坏、弯扭破坏、扭转破坏;剪跨比减小后,破坏形态由弯扭破坏转变为剪扭破坏;OTSRC柱的扭矩-扭转角滞回曲线存在明显的捏缩现象,荷载-柱顶位移滞回曲线为饱满的梭形;扭弯比由0.42增至∞时,OTSRC柱的受扭承载力提高146.8%,其抗扭刚度退化减慢,抗弯刚度退化加快;增大腹杆配箍率对OTSRC柱的变形性能影响较小;OTSRC柱的受弯耗能能力优于受扭耗能能力,因此其在复合受扭状态下易发生扭转破坏;在压-弯-剪-扭复合受力状态下,为保障OTSRC柱的层间位移角满足设计要求,剪跨比应不小于2.5。
In order to reveal the seismic behavior of open-web trussed steel reinforced concrete(OTSRC)columns under compression-flexure-shear-torsion combined actions,ten OTSRC columns were tested,in which parameters such as torsion-bending ratio,axial compression ratio,shear span ratio,stirrup ratio and concrete cover thickness were considered.The failure characteristics of specimens under composite torsional conditions were observed,and the influences of different parameters on the seismic indexes of OTSRC columns,such as hysteretic curve,skeleton curve,ductility,energy dissipation,stiffness degradation were analyzed.The results show that with the increase in torsion-bending ratio,the failure modes of OTSRC columns are bending failure,bending-torsion failure and torsion failure in turn.The failure mode of the specimens changes from bending-torsion failure to shear-torsion failure with the decrease of shear span ratio.The torque-torsion angle hysteresis curves have obvious pinching phenomenon,and the load-displacement hysteric curves present full spindle shapes.As the torsion-bending ratio increases from 0.42 to∞,the torsional capacity of OTSRC column increases by 146.8%,the degradation of torsional stiffness slows down and the degradation of flexural stiffness accelerates.Increasing the stirrup ratio has little effect on the deformation performance of OTSRC columns.The bending energy dissipation capacity of OTSRC column is obviously superior to torsional energy dissipation capacity,so OTSRC column is more susceptible to torsional failure under combined torsional state.In order to ensure that the interlayer displacement angle of OTSRC columns meets the design requirements under compression-flexure-shear-torsion combined actions,the shear span ratio should not be less than 2.5.
作者
陈宇良
吉云鹏
陈宗平
CHEN Yuliang;JI Yunpeng;CHEN Zongping(School of Civil Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China;Key Laboratory of Disaster Prevention and Structure Safety of the Ministry of Education,Guangxi University,Nanning 530004,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2023年第7期70-79,共10页
Journal of Building Structures
基金
国家自然科学基金项目(51908141)
广西自然科学基金项目(2019GXNSFBA245030)
中国博士后科学基金项目(2021M693854)。
关键词
空腹式角钢骨架混凝土柱
压-弯-剪-扭
复合受力
拟静力试验
抗震性能
open-web trussed steel reinforced concrete column
compression-flexure-shear-torsion
combined action
quasi-static test
seismic performance
