SRC-RC竖向混合结构转换柱侧移刚度试验研究

EXPERIMENTAL STUDY ON LATERAL STIFFNESS OF TRANSFER COLUMN IN SRC-RC HYBRID STRUCTURE

对16根转换柱试件和1根钢筋混凝土柱对比试件采用"建研式"加载设备完成了低周反复荷载试验,用于研究转换柱的基本抗震行为。建立了转换柱中钢与混凝土的相互作用方式及型钢的受剪模型,并以此为基础分析了型钢延伸高度、型钢配钢率、箍筋配箍率及轴压比对转换柱侧移刚度及侧移刚度退化速率的影响。采用反弯点法计算了转换柱的弹性侧移刚度。通过对试验数据的回归分析,同时引入截面抗弯刚度折减系数用于考虑裂缝及混凝土塑性发展的影响,得到了转换柱屈服点侧移刚度的计算公式,计算值与试验值吻合。

Experiments of 16 transfer columns and one reinforced concrete column under low cyclic reversed loading were carried out to research the seismic performance of transfer columns. An interaction model between concrete and shape steel was established. The shear model of shape steel was also brought forward for the analysis on the lateral stiffness of the transfer column in a SRC-RC hybrid structure. The lateral stiffness of a transfer column and the degeneration ratio of lateral stiffness are affected by the parameters of volumetric ratios of stirrups, the axial compressive ratio, area ratio of shape steel and extension length of shape steel. A contraflexure point method was employed to calculate the lateral stiffness of elasticity. Through the regression analysis of test data, the formula for lateral stiffness in a yield condition was put forward, which takes the plastic development of concrete and cracks into account. The calculated results agree well with the test data.