Review of recently constructed buildings that combine steel frames and concrete walls

Abstract

Recent building construction in New Zealand has exhibited an increase in the use of structural steel due to its availability and perception of good seismic performance. Despite the renewed popularity of structural steel framing, concrete walls remain a common choice of lateral force resisting system, leading to a trend of 'hybrid' buildings that combine steel frames and concrete walls. This study aims to understand and characterise this building type, focusing on buildings constructed in Auckland and Christchurch from 2014 onwards. Through sidewalk surveys and desktop research, an initial list of buildings of interest was developed, and structural drawings were obtained from council property files or from structural engineers. The drawings were examined and relevant typological information identified, including building use, importance level, ductility, building height, wall configuration, wall construction method, steel framing system, connection details, and suspended floor system. Buildings were classified according to their lateral load-resisting system in two directions, resulting in the categorisation of five distinct building types that represent these new ‘hybrid’ buildings. Further investigation of the building types and connection detailing will identify critical aspects of this hybrid system that need verification by testing and modelling.