高轴力下钢筋混凝土异形柱节点受力性能研究

由于异形柱特殊的截面形式,地震作用下,较高轴压比时异形柱节点与普通矩形柱节点相比破坏更为严重。通过钢筋混凝土异形柱边节点和中间节点低周反复荷载试验,分析了高轴力下异形柱边节点和中间节点核心区混凝土裂缝发展及破坏情况,并利用试验数据计算得到节点核心区受剪承载力,最后结合节点核心区箍筋应变变化规律初步探讨了异形柱节点的抗剪机理。研究表明,高轴力下异形柱节点剪力较大,核心区腹板混凝土开裂破坏较严重,成为异形柱结构抗震的一个薄弱环节,限制了异形柱结构楼层高度。

Research in mechanical behavior of RC joints with specially shaped columns under high axial force

Because of special section shape,the joints with specially shaped columns under high axial compression ratio will damage more seriously than the joints with ordinary rectangular columns when suffering earthquakes.Through the low frequency cyclic loading experiment of an exterior joint and a middle joint with specially shaped column,the development and destruction of concrete cracks of the joints with specially shaped columns under high axial force were analyzed,the shearing strength of the joints core were calculated by experiment data,and the shear mechanism of the joints with specially shaped column was investigated combined with the stirrup strain distributed in joint core.It is shown that the joint with specially shaped column under high axial force have larger shear,and the concrete in web of joint core will be cracking more seriously,so joints become the weakness site of the structure with specially shaped columns,thus restricting the storey height of structure.