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

A seismic assessment of an existing 32-story reinforced concrete framed tube building is performed using inelastic dynamic time-history analysis to obtain force and deformation response of the structure subjected to three ground motion records. Details of the modeling based on the DRAIN-2D program, plastic rotation, rotation and curvature ductility demands and capacity evaluation of members are discussed. Recent recommendations for plastic hinge rotation and plastic hinge length modifications are discussed and the results of the application of some of these recommendations are evaluated. Some observations with regard to shear 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.