内置钢箱—混凝土组合梁正截面承载力计算方法研究

Research on Calculation Method for Flexural Bearing Capacity of Encased Steel Box Concrete Beam

内置钢箱—混凝土组合梁在既有房屋的套建增层改造及巨型框架的建造中具有广阔的应用前景。由于钢箱与混凝土的接触面积相对较小,且钢箱对其腹板两侧混凝土无法形成如内置H型钢对混凝土的有效约束,这些特点使得内置钢箱—混凝土组合梁的正截面承载力计算方法不同于内置H型钢—混凝土组合梁。针对这一问题,给出以平截面假定为基础的内置钢箱—混凝土组合梁正截面受弯承载力计算公式,并得到了折减系数的取值,从而得到符合内置钢箱—混凝土组合梁自身特点的正截面受弯承载力计算公式。

Encased steel box concrete beam （ESBCB） has brilliant prospect in reconstructing the existing buildings and constructing the mega structure buildings. The touching area of steel box usually is relatively smaller, and the steel box can not restrain the concrete beside the web effectively as that of the encased H-steel, which makes the calculation method for the flexural bearing capacity of ESBSBs different from that of encased H-steel concrete beam. In consideration of this problem, the calculation formulas for the flexural bearing capacity of ESBSBs are perfected, which is based on the Plane Section Assumption. The value of the reduction factor is given. Finally, the calculation formulas for the flexural bearing capacity of ESBSBs which conform to their characteristics are got.