INFLUENCE OF BUILDING HEIGHT AND GROUND MOTION TYPE ON THE SEISMIC BEHAVIOUR OF ZIPPER CONCENTRICALLY BRACED STEEL FRAMES

摘要

This paper presents an analytical study of the response of 4-, 8-, and 12-storey concentrically braced steel frames with zipper columns under three different seismic ground motions: regular crustal earthquakes, near field earthquakes and long duration subduction earthquakes. A design procedure proposed to ensure elastic zipper column response was found adequate for most cases but tension forces exceeding the predicted loads developed in the lower floors of the 8- and 12-storey buildings. The performance of all structures was satisfactory under the regular motions. Collapse by dynamic instability occurred for the 8- and 12-storey structures under near field and subduction earthquakes.