考虑二次受力圆形钢套管加固钢筋混凝土短柱轴心受压承载力研究

Study of Bearing Capacity of Reinforced Concrete Short Column Strengthened by Circular Steel Tube under Axial Loading Considering Twice Loading

为了研究圆形钢套管加固钢筋混凝土短柱在二次受力下的基本力学性能,首先进行了1根未加固的普通钢筋混凝土柱和2根圆形钢套管加固钢筋混凝土柱的轴心受压试验,其中1根柱通过对其施加后张预应力来模拟构件加固前的初始轴压力;其次,依照试验参数,应用有限元数值模拟加固柱在不同轴压比下的力学性能;最后建立了圆形钢套管加固钢筋混凝土短柱在二次受力下的轴心受压承载力计算公式。结果表明:无论是否有初始轴压力,加固柱承载力均比未加固柱高很多,但是二次受力下的加固柱的轴心受压承载力会略有降低,且承载力会随着轴压比的增大而减小;应用有限元数值模拟的结果和应用承载力公式计算出的结果均与试验结果吻合良好。

To study the basic mechanical performance of reinforced concrete short column strengthened by circular steel tube considering the twice loading, one unstrengthened reinforced concrete column and two reinforced concrete columns strengthened by circular steel tube are tested under axial loading, and post prestressing force was supplied to one of the strengthened columns to simulate the original axial load before strengthening. Then, based on the experimental parameters, the numerical model of FEA is set up to imitate the mechanical performance of strengthened column under different axial compression ratio. At last, a formula of strengthened column bearing capacity considering the twice loading is derived. The results show that the capacity of the strengthened columns grows up more than unstrengthened column whatever there is original axial compression or not, but the bearing capacity of strengthened column considering the twice loading are less than the column considering the first loading, and the capacity is decreased with the increase of the axial compression ratio. The computing results is tallied with the experimental results and numerical result.