11.25: Rocking damage‐free steel column base with friction devices: Design procedure and global seismic response of buildings

Abstract

ABSTRACTResilient minimal‐damage steel frames, such as post‐tensioned self‐centering steel frames or steel frames with passive dampers, have been extensively studied but little attention has been paid to their column bases. This paper presents a rocking damage‐free steel column base using post‐tensioned high strength steel bars to control rocking behavior and friction devices that provide stable energy dissipation capacity. Contrary to conventional steel column bases, the monotonic and cyclic hysteretic moment‐rotation behavior of the proposed column base can be easily described using simple analytical equations. The paper describes in detail a step‐by‐step design procedure for the column base that ensures damage‐free behavior and adequate self‐centering and energy dissipation capacity. A finite element model for the column base is developed in OpenSees and used to conduct nonlinear dynamic (seismic) analyses of a building using self‐centering steel moment‐resisting frames. The results of the analyses show that the column base helps the building to avoid damage in the 1st story columns along with eliminating the 1st story residual drifts under both the design and maximum considered earthquake intensities.