Seismic evaluation of an existing reinforced concrete framed tube buildingbased on inelastic dynamic analysis

A seismic assessment of an existing 32-story reinforced concrete framed tub e building is performed using inelastic dynamic time-history analysis to ob tain force and deformation response of the structure subjected to three gro und motion records. Details of the modeling based on the DRAIN-2D program, plastic rotation, rotation and curvature ductility demands and capacity eva luation of members are discussed. Recent recommendations for plastic hinge rotation and plastic hinge length modifications are discussed and the resul ts of the application of some of these recommendations are evaluated. Some observations with regard to sheer lag effect are presented and some of the difficulties in using the direct results of inelastic dynamic time history analysis in seismic assessment for practical applications are demonstrated. (C) 2000 Elsevier Science Ltd. All rights reserved.