EXPERIMENTAL RESEARCH ON SEISMIC BEHAVIOR OF FRAME SIDE JOINTS IN STEEL HIGH- STRENGTH REINFORCED CONCRETE WITH DOG- BONE CONNECTIONS

The seismic behavior of frame side joints of the steel high-strength reinforced concrete with dog-bone type weakening has been investigated based on the experiment and analysis of nine joint specimens,under cyclic loading. The test results show that well designed HSRC frame joint with dog-bone type weakening has good displacement ductility and hysteretic behavior.The joint,whose axial compression ratio is small,hysteretic curve is full and skeleton curve is gentle,has a better ductility and energy dissipation.In condition of the same or close axial compression ratio,the seismic performance,including the ductility and energy dissipation capacity of the joint with dog-bone type weakening is clearly superior to that of the ordinary joint,and the displacement ductile coefficient is increased by 10% to 25%. When the dog-bone type weakening is taken on the flanges of the steel at the beam end near the joint,the plastic hinge of the beam may be transferred from the root of beam end to the weakened position, thus the seismic behavior of the joints may be improved effectively and the ductile design can be realized．