T形柱正反向受剪承载力和变形能力特性研究

Research on Shear Capacity and Deformation Capacity of T Shaped Column under Forward and Reverse Loading

由于T形柱特殊的截面形式,正反向受剪时将分别处于腹板受压、翼缘受拉和腹板受拉、翼缘受压两种状态,故其正反向受剪承载力和变形能力与十字形柱相比差异较大。通过对国内T形柱受剪承载力试验进行分析,探讨了T形截面柱正反向受剪承载力特性,并对某一T形柱进行低周反复荷载试验,分析了低剪跨比状态下T形柱正反向加载破坏特征、承载能力和变形能力特性。研究表明,T形柱截面不规则,当狭义剪跨比小于3.0时,正反两个方向受剪承载能力和变形能力存在显著差异,两个方向的抗震性能亦存在差异,腹板受压时,柱脚腹板混凝土破坏严重,降低了异形柱的截面刚度和承载力,成为异形柱结构的薄弱部位。

Because of the special section of T shaped columns,the web will bear pressure and the flange will bear tension or the web will bear tension and the flange will bear pressure under forward and reverse load,it is different to the shear capacity and deformation capacity of＂＋＂ shaped column under forward and reverse load.This paper analyzed the shear experiments of T shaped columns in China,investigated the experimental characteristics of shear capacity and deformation capacity about T shaped columns under forward and reverse load.Through low frequency cyclic loading experiment of T shaped column,investigated the failure characteristic,the shear capacity and deformation capacity characteristic of T shaped column with low shear-span ratio.It is shown that when the narrow sense shear-span ratio is less than 3.0,the shear capacity and deformation capacity of the T shaped column are different obviously under forward and reverse load because of the irregular section,that is to say the seismic behavior of two directions is different.The web concrete in column foot will damage seriously while the wed bearing pressure,which lower the section stiffness and shear capacity,so the column foot maybe become the weakness position of structure with specially shaped columns.