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

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.