基于统一强度理论的钢管自应力混凝土柱极限承载力研究

Research on Ultimate Bearing Capacity of Self-stressing Concrete-FilledSteel Tube Based on Unified Strength Theory

为预测钢管自应力混凝土柱的极限承载力,基于双剪统一强度理论,对钢管自应力混凝土轴压柱进行受力分析,引入长细比折减系数,考虑混凝土自应力从而得到了约束系数k的计算新公式,构建了一种新的钢管自应力混凝土柱极限承载力理论计算方法。将该计算方法分析的结果与已有试验数据进行对比,两者吻合良好。进一步分析了混凝土强度、钢材屈服强度、自应力值、钢管壁厚和钢管外径对钢管自应力混凝土柱轴压极限承载力的影响,各因素的影响顺序为:钢管外径>钢管壁厚>混凝土强度>钢材屈服强度>自应力值。

By using self-stressing concrete can improve the coordination between steel tube and concrete and meet the practical engineering requirements.In order to predict the ultimate bearing capacity,the stress analysis of self-stressing CFST column under axial compression was carried out based on twin-shear unified strength theory.The reduction factor of slenderness ratio was introduced and the self-stressing of concrete was considered for calculating constraint coefficient k.A new theoretical calculation method for the ultimate bearing capacity of self-stressing CFST column was established.The results obtained by this method were in good agreement with available experimental data,and the effects of concrete strength,steel yield strength,self-stress value,steel tube wall thickness and steel tube outer diameter on the ultimate bearing capacity of self-stressing CFST column were further analyzed,the influencing order of each factor was:steel tube outer diameter>steel tube wall thickness>concrete strength>steel yield strength>self-stress value.