SEISMIC PERFORMANCES EVALUATION OF STEEL REINFORCED CONCRETE TRANSFER STRUCTURE WITH ENERGY DISSIPATION HAUNCH BRACE

摘要

Transfer structures are widely adopted in high-rise buildings to meet the need of buildings with multi-functions.But earthquake experiences reveal that this kind of vertical irregular structure will have severe damage due to the abrupt changes of stiffness and strength at the transfer story.To improve the seismic performances of reinforced concrete(RC)transfer structures,a kind of new transfer structure,steel reinforced concrete(SRC)transfer structure with buckling-restrained energy dissipation haunch brace(EDHB)was proposed by utilizing steel-concrete composite technology and energy dissipation technology.Based on the validity of the numerical analysis model,a large number of nonlinear dynamic time history analyses of the 10-story SRC transfer frame structure were carried out.Considering the influence of the uncertainty of ground motion on the dynamic time history analysis,24 ground motions are selected and classified into three types according to the magnitude and distance to source.The incremental dynamic analysis(IDA)was adopted to compare the seismic performances of normal RC transfer frame structure and the new transfer structure,and the effects of SRC components and buckling-restrained EDHBs on the seismic behaviors of the RC transfer structure were studied.Results show that the maximum inter-story drift angles at the transfer story can be reduced from 20％to 80％under the three-type ground motions.The seismic responses of transfer story can be decreased significantly by buckling-restrained EDHBs.Through comparing the decrease of the slope of the IDA curve,the limit value of maximum inter-story drift angle in different performance can be confirmed.The deformation capacity of the SRC transfer frame structure with buckling-restrained EDHB can be 1.24 to 1.33 times and 1.73 to 2.38 times that of SRC transfer structure and normal RC transfer structures corresponding to different performance levels.It is demonstrated that the seismic performances of transfer frame structure can be improve by buckling-restrained EDHBs.