中空夹层钢管混凝土长支撑构件受压性能研究

Research on Compression Behavior of Long Support Member of Concrete-filled Double-skin Steel Tubes

针对地铁基坑支护的支撑选取问题,提出了一种中空夹层钢管混凝土长支撑构件,采用有限元软件ABAQUS对构件进行模拟,研究其在压力作用下的承载能力及破坏特性,并分析了长径比、空心率对其轴压力学性能的影响以及长细比、荷载偏心距、空心率对其偏压性能的影响。结果表明:长径比对中空夹层钢管混凝土长支撑构件的轴心受压性能有显著影响,空心率对轴心受压性能影响不大;长细比、荷载偏心距对中空夹层钢管混凝土长支撑构件的偏心受压性能有显著影响,空心率对偏心受压性能影响不大;现有短构件受压极限承载力计算公式同样适用于本文提出的长构件。

A type of concrete-filled double-skin steel tube(CFDST)long support member is put forward to solve the problem of selecting subway foundation pit support.The finite element software ABAQUS was used to simulate the member.The failure mode and bearing capacity under compression were studied.The influence of length-to-diameter ratio and hollow rate on the axial compression behavior and the influence of slenderness ratio,load eccentricity and hollow rate on the eccentric compression behavior were analyzed.The research results show that the length-to-diameter ratio have significant effects on the axial compression behavior of the CFDST long support member,and the hollow rate has little effect;the slenderness ratio and load eccentricity have significant effect on the eccentric compression behavior of the CFDST long support member,and the hollow rate has little effect.The existing calculation methods of CFDST short members are also applicable to long members put forward in this paper.