Experimental Study On Seismic Behavior Of Reinforced Concrete Frame Retrofitted With Single-diagonal Buckling-restrained Braces

Earthquake disaster is the main cause of the building damage.Under strong earthquake reciprocating driving,it may causes houses destroy and personal casualty.it will bring huge losses to the society.Buckling restrained brace is an innovate brace with excellent energy dissipation behavior and seismic performance.This kind of brace is only connected with the other components of the core plate,all of the load is borne by the core board,the outer sleeve and the packing material only constrain the buckling of the core board that makes the core board can enter the yield stage no matter tension or compression.On the one hand,the buckling restrained brace can avoid the ordinary brace’s defects of the difference of the tension and compression bearing capacity.On the other hand,the buckling restrained brace can provide the energy dissipation capacity which likes the metal damper’s capacity,which act as a fuse in the structure.The buckling restrained brace remain structure in the elastic range.Therefore,the application of buckling restrained brace can comprehensively improve the seismic behavior of common frame in the moderate and major earthquake.Two frame specimens,including a reinforced concrete frame with BRB and one without for comparison,were tested under low reversed cyclic pseudo-static loading,respectively.The test demonstrates comparison of the characteristics between two frame specimens,such as concrete element cracking,lateral load-displacement loop,skeleton curve,lateral stiffness,energy-dissipating performance,and the equivalent viscous damping ratio to investigate the effect of single-diagonal brace.The results show that single-diagonal bucking-restrained braces can effectively improve the seismic performance of the reinforced concrete frame with plumped hysteretic curve,larger lateral stiffness,and a significant increase in energy dissipation and damping ratio.This paper also introduces some conditions in the structure design of the actual project.Based on the analysis and calculation of the two structures of the surplus building section by YJK software,the improvement of the whole building structure with buckling restrained brace is explained in the practical engineering design,which through the standard of some control parameters to be corroborated.Calculation results shows that buckling restrained brace(BRB)not only effectively improves the lateral stiffness and torsional rigidity,but also successfully solve the original structure of the program period ratio and interstory drift which do not meet the standard requirements and improve the overall structure of the seismic performance.