Displacement-based seismic retrofit design for non-ductile RC frame structures using local retrofit interventions at beam-column joints
In the past design codes, infill panels/walls within frame buildings have been considered as non-structural elements and thus have been typically neglected in the design process. However, the observations made after major earthquakes even in recent times (e.g. Duzce 1999, L’Aquila 2009, Darfield 2010) have shown that although infill walls are considered as non-structural elements, they can interact with the structural system during seismic actions and modify the behaviour of the structure significantly. More recent code design provisions (i.e.,NZS4230, Eurocode 8, Fema 273) do now recognize the complexity of such interactions and require either a) consider these effects of frame-infill interaction during the design and modelling phase or b) assure no or low interaction of the two systems with proper detailing and arrangements in the construction phase. However, considering the interaction in the design stage may not be a practical approach due to the complexity itself and in most cases does not solve the actual problem of brittle behaviour and thus damage to the infills. Therefore, the purpose of this particular research is to develop technological solutions and design guidelines for the control or prevention of damage to infill walls for either newly designed or existing buildings. For that purpose, an extensive experimental and numerical research programme has been planned. The concept, background on infill practice in New Zealand and the research programme will be briefly described in this paper.