钢管混凝土叠合柱施工偏差对极限承载力的影响

The influence of construction deviation on the ultimate bearing capacity of concrete filled steel tubular columns

钢管混凝土叠合柱高墩在施工过程中模板或钢管安装发生偏差容易导致极限承载力下降,然而采用传统的线弹性分析方法常不能有效的计算该部分下降.为更加准确的模拟施工偏差对钢管混凝土承载能力的影响,采用ABAQUS及其非线性梁板单元,充分考虑几何非线性和材料非线性,通过线弹性屈曲和非线性后屈曲分析计算,详细研究了施工偏差对钢管混凝土叠合柱桥墩极限承载力所产生的影响.结果表明:随着钢管混凝土叠合柱桥墩顶部偏移值的增大,其极限承载力也在逐步减小,说明施工偏差导致整个钢管叠合柱桥墩发生弯曲之后,极大地降低了桥墩的极限承载力.该承载力的下降呈现显著的几何非线性,荷载和施工偏差存在二阶效应,所以在实际施工过程中,要严格控制钢管安装时的误差.

In the construction process, the ultimate bearing capacity of the concrete filled steel tubular columns will be reduced if the template or the steel tubular installation is deviated. However, the traditional linear elastic analysis method can＇t calculate it effectively. To find the influence of construction deviation on ultimate bearing capacity of concrete filled steel tubular columns, this paper studies it in detail by using the ABAQUS and its nonlinear beam-shell element, and fully considers the geometric and material nonlinearity. The result shows that the ultimate bearing capacity will decrease gradually as the deviation increases, which tells the fact that the ultimate bearing capacity will be greatly reduced when the whole concrete filled steel tubular columns are bended because of the deviation. So the deviation factor in the steel tubular installation should be strictly controlled in the actual construction process.