波纹钢管-钢夹层复合管混凝土柱轴压力学性能研究

Behavior of CSP-interlayer-steel tubular concrete short columns under axial compression

为改善耐腐蚀能力,提出了在传统钢管混凝土外套波纹钢管形成的波纹钢管-钢夹层复合管混凝土新型组合构件。针对此类构件,开展了短柱轴压试验,观测了在轴压荷载作用下的破坏模式,分析了外部波纹钢管的应力应变特点,并通过理论分析与同等条件的钢管混凝土进行了对比。结果表明:波纹钢管除防腐保护作用外,还能为内部材料提供较强的约束作用,新型组合柱相比于同等条件的钢管混凝土承载力提高了10.1%,延性系数提高了35.6%;相对于内部钢管混凝土承载力提高了136%,位移延性系数提高了55.7%。基于试验采用ABAQUS建立并验证了相应的有限元模型,并对影响新型组合构件轴压承载力的关键参数进行了分析,在现有钢管混凝土轴压承载力计算公式的基础上,推导了新型组合构件的轴压承载力计算公式,公式预测结果与有限元分析结果吻合良好。

In order to improve the corrosion resistance, a new type of composite member of corrugated steel pipe(CSP)-interlayer-steel tubular concrete(CICFST) columns(i.e. concrete-filled steel tubular(CFST) structures jacketed with CSP) is proposed. Axial compression tests on CICFST stub columns were carried out. The failure modes of CICFST and the stress-strain characteristics of CSP were discussed in detail. The comparison between CICFST and CFST under the same conditions were also carried out. The experimental results indicate that besides the anticorrosive protection, CSP can also provide enough confinement for the internal CFST. Compared with the CFST under the same conditions, the bearing capacity and ductility index of CICFST are increased by 10.1% and 35.6%, respectively. Compared with the internal CFSTs, the bearing capacity is increased by 136% and the ductility index is increased by 55.7%. Based on the experiments, a suitable finite element model was established and validated. The key parameters, which affect the bearing capacity of CICFST, were analyzed. Based on the existing formulas for calculating the bearing capacity of CFST, the method for predicting the bearing capacity of CICFST was proposed. The predicted results of the formulas are in good agreement with the results of the finite element analysis.