EXPERIMENTAL STUDY ON SEISMIC BEHAVIOUR OF NEW REINFORCEMENT SCHEME DEEP COUPLING BEAMS

Seismic behaviors of 9 coupling beam specimens were investigated experimentally. Effects of span-to-depth, amount of stirrups and longitudinal bars of coupling beam on its failure mode are studied, as well as the hysteretic behavior, stiffness degradation, deformation and energy dissipation capacity. Coupling beams with span-to-depth of 0.75―1.5 were observed to suffer shear failure or flexural-shear failure, no matter whether longitudinal reinforcements yield or not. The existing of stirrups along the height of the beam effectively improved its deformation and energy dissipation capacity. According to test results, the formulae for estimating shear strength of the coupling beam were suggested considering the effect of longitudinal reinforcements. Estimated shear strength of coupling beams agreed well with the experimental data.