Assessment of Redundancy Factors for the Seismic Design of Special Moment Resisting Reinforced Concrete Frames

Abstract

A parametric study devoted to assess the impact of increasing the structural redundancy in ductile reinforced concrete (RC) moment framed buildings is presented. Among the studied variables were the number of stories and the number of bays. Studied models were 4, 8, 12 and 16-story frames with a story height h=3.5 m (11.5 ft). Nonlinear static analyses were used to evaluate numerically redundancy factors. Based on the results of this research and previous studies reported in the literature, it can be concluded that it is justified to account directly structural redundancy in the design by using a redundancy factor, as proposed and done in some international building codes.

Keywords:
structural redundancy; redundancy factor; seismic codes; reinforced concrete moment frames; ductility; overstrength