Experiment On Seismic Behavior Of Steel Reinforced Concrete Frames With Reduced Beam Sections

Compared with reinforced concrete (RC) structure, steel reinforced concrete (SRC) structure has characteristics of high bearing capacity and good ductility, so has been applied in engineering widely. However, under action of strong earthquake, plastic hinge at beam end may induce brittle fracture of welded joint between beam and column and entry joint core, which may reduce the seismic behavior of the SRC structure significantly. In this dissertation, a dog-bone type reduced beam section is proposed for steel flanges at beam end so as to transfer the plastic hinge from the beam end to the reduced beam section. This may improve the seismic behavior of the SRC structure, and has important significance in theory and value in engineering.In this dissertation, the experimental investigation on seismic behavior of SRC frame structure with dog-bone type reduced beam section is systematically performed, and the main research works and results include:(1) A 1/3 scale model of SRC frame with reduced beam sections is designed and fabricated. From the similitude between the original frame and the specimen, the specimen different members are designed. This design includes a detailed calculation of flexural strength, shear strength and internal forces of the frame members, satisfying seismic requests. A push-over analysis has been done on the designed model frame to study its Elastic-Plasticity performance.(2) An experimental investigation to study the seismic behavior of the designed SRC frame structure with"dog-bone type"reduced beam sections. Through a test on a two-span, three-story 1/3 scaled SRC frame model under cyclic loading, the bearing capacity, ductility, stiff degeneration, ability of energy dissipation, hysteretic characteristics, failure mechanism of the frame structure and the function of"dog-bone type"reduced beam sections on integral bearing capacity of the frame are studied. The design method for seismic capacity of SRC frame structure is further investigated.The results show that the SRC frame structure with"dog-bone type"reduced beam sections has good ductility, strong deformation ability,high energy dissipation and bearing capacity, so as to meet the requirement for the seismic behavior of general ductile frame. Then the use of"dog-bone type"reduced beam section improves the seismic capacity of the SRC frame structure.