钢管混凝土轴压短柱的极限承载力分析

基于双剪统一强度理论，充分考虑了中间主应力，即钢管和核心混凝土之间的相互作用力（紧箍力）的影响，推导出了钢管混凝土轴心受压短柱的承栽力公式。该公式不仅考虑了紧箍力对混凝土的约束作用，而且考虑了紧箍力对钢管的环向张拉作用，并对其侧压系数和材料强度参数的取值做了分析探讨，最后将计算结果与文献资料的试验数据进行了对比。结果表明：双剪统一强度理论对钢管混凝土构件的研究有很好的适用性；考虑紧箍力对钢管承载力的影响是非常有必要的；该研究为钢管混凝土结构的优化设计提供了可靠的理论依据。

Analysis of Ultimate Bearing Capacity of Concrete-filled Steel Tubular Axial Compression Short Columns

According to the bearing Capacity of concrete-filled steel tubular axial compression short columns, based on the twin-shear unified strength theory, the calculation formula of bearing capacity of concrete-filled steel tubular members subjected to axial compressive short columns was derived. In this formula, the intermediate principal stress and the reciprocity force between strain-constrained concrete cylinders and steel tube were considered sufficiently. The restrain action of concrete and the circumferential stretching of the steel tube both produced by the reciprocity force were taken into account, these made the compressive strength of concrete enhanced, and made the compressive strength of the steel tube reduced. The values for lateral pressure coefficients and for material strength parameters were analyzed and discussed. A comparison between the theoretical results and the experimental data in the literature was achieved. The results indicate that the twin-shear unified strength theory is versatile in the theoretical analysis of concrete-filled steel tube and considering the effect of the reciprocity force is very necessary. The reliable theoretical foundation can be provided for the optimum design of concrete-filled steel tube.