套箍系数及偏心距对薄壁钢管高强混凝土短柱力学性能影响

Influence of confinement index and eccentricity ratio on the mechanical properties of high strength concrete-filled thin steel tubular columns

本文研究了偏心率及套箍系数对钢管混凝土偏压柱的力学性能的影响,对比分析了承载力实验值与几部国内典型圆钢管混凝土规程的计算值,计算了不同套箍系数对大小偏压试件承载力的影响。结果显示,偏心率越小,钢管的纵向应变对应的环向应变越大,外部钢管对核心混凝土的套箍效应越明显,试件的极限承载力越高,横向变形能力越差;建议在结构设计时优先选用规程CECS 254:2012作为依据,并尽量选用小偏心的荷载布置方式,以更好利用材料的力学性能。

Influences of confinement index and eccentricity ratio on the mechanical properties of concrete filled steel columns subject to eccentric compression were analyzed. In this study,the experimental values of the load in each test were compared with the design values specified by the national standard,and the bearing capacity of specimens with different confinement index was calculated. The analysis results show that the smaller the eccentricity,the larger the circumferential strains corresponding to the longitudinal strains of the steel tube,the more significant the confining effect of the steel tube,the higher the bearing capacity of the component and,accordingly,the lower the capacity of lateral deformation. Therefore,the present analysis results suggest that,when conducting structural design,Standard of CECS 254：2012 be firstly referred to and loadings with as less eccentricity as possible be adopted so as to better utilize the mechanical properties of the materials.