PBL加劲型方钢管混凝土短柱轴压承载力统一解

对于特定的PBL加劲型方钢管混凝土轴压短柱,考虑混凝土榫形成的剪力键提供的有效作用,对PBL加劲肋进行受力分析.引入混凝土有效约束系数,采用统一强度理论,考虑中间主应力和材料拉压比的影响,推导了PBL加劲型方钢管混凝土短柱轴压极限承载力的计算公式,并对其影响因素进行了分析.将计算结果与文献试验结果进行对比,吻合较好,验证了所给公式的正确性.研究结果表明,PBL加劲型方钢管混凝土短柱的轴压承载力随双剪统一强度理论参数b、混凝土内摩擦角、加劲肋的宽度和厚度的增大而提高.所得结果可以为PBL加劲型方钢管混凝土短柱轴压承载力的研究提供参考.

UNIFIED SOLUTION OF ULTIMATE BEARING CAPACITY FOR CONCRETE-FILLED STEEL SQUARE TUBULAR SHORT COLUMN STIFFENED WITH PBL

Aiming at the specific concrete-filled square steel tubular short column stiffened with PBL under axial compression load, and considering the useful effect of the PBL shear connectors, the mechanical behavior of PBL stiffening ribs was analyzed. Introducing into the effective constraint coefficient of concrete, based on the unified strength theory and also considering the impact of the intermediate principal stress and tension-compression ratio of the material, formulas for calculating the ultimate bearing capacity were deduced, the influencing factors were analyzed as well. Compared with the test results in relevant documents, they coincided well with each other, which verified the correctness of the formula. The result shows that the ultimate bearing capacity of the concrete filled steel square tubular column with PBL is significantly improved with the increase of parameter b, the concrete friction angle and the width and thickness of the ribs. The solution can provide a reference for the study on the ultimate bearing capacity of the concrete-filled steel square tubular column with PBL.