EQUIVALENT FRAME ANALYSIS OF FLAT-PLATE BUILDINGS FOR SEISMIC LOADING

An equivalent frame approach is presented for nonlinear seismic analys is of reinforced-concrete flat plate buildings. The approach employs a parametric hysteretic model and is based on the effective slab-width concept. Unlike in the previous equivalent frame approaches, the propo sed method targets both the moment-transfer capacity as well as stiffn ess of the interior and exterior slab-column connections. The hysteret ic parameters and the effective slab width factors are determined from results of laboratory tests on slab-column connections for the class of flat plate buildings constructed prior to the 1960s with reinforcin g detail typical of gravity load design. The validity of the approach is justified by comparing the calculated and the measured responses of two-bay flat plate subassemblies tested under earthquake-type loading . With the proposed equivalent frame approach, the response of flat pl ate buildings for seismic loading could be predicted more realisticall y over a wide range of lateral drift levels.