Assessment of static nonlinear approaches for earthquake-resistant design of tall reinforced concrete buildings

The simplified nonlinear static procedures (conventional pushover) have become a useful tool to assess the seismic performance of buildings. Beyond their inherent static character, such methods include two major inaccuracies: poor consideration of the higher-mode effects and lack of consideration of the changes in the modal characteristics of the structure (mainly, the modal shapes) as the damage progresses; both issues are particularly relevant for tall buildings. To cope with these two subjects, the modal and adaptive pushover strategies have been proposed, respectively. The objective of this paper is to evaluate the suitability of these procedures for high-rise buildings. The research approach consists in selecting two representative prototype buildings with 30 and 45 stories and carrying out a number of nonlinear static and dynamic analyses and comparing their results. Preliminary results show that current pushover methods cannot predict with enough accuracy the response of high-rise buildings under dynamic seismic action