Parametric Analysis of Prestressed Precast Concrete Frames with Buckling-Restrained Braces
To promote the application of precast concrete frames in earthquake hazard areas,a new pres-tressed precast concrete frame with buckling-restrained braces(BRB-PPCF)was proposed,and the nonlin-ear dynamic time-history analysis of 6-story,9-story and 12-story BRB-PPCF cases under 20 earthquake waves were carried out.The results showed that the average maximum inter-story drift ratios θmax of BRB-PPCFs were less than 2.0%and the maximum residual inter-story drift ratios θr were less than 0.5%under both rare and extremely rare seismic intensity.The θmax and θr values of BRB-PPCFs gradually decreased with the decrease of the initial stiffness ratio αc between the moment-resistant sub-frame(MSF)and the truss sub-system(TSS).Reducing the αc value of BRB-PPCF effectively improved its seismic performance and post-earthquake recoverability.The θmax and θr values of BRB-PPCFs decreased first and then increased with the increase of the ratio ψ of the MSF inter-story shear force at linear limit state and the TSS shear force at yield state,and the influence of the ψ was relatively small.The effects of the ratio σpi/σpl between the initial tensile stress and the proportional ultimate strength on the θmax and θr values of the BRB-PPCF could be ignored.