Impact of combined seismic and energy renovation works on the dynamics and damageability of infilled RC frame buildings

This study aims to explore how combined seismic and energy related renovations of external infills affect the overall dynamic response and seismic damageability of framed buildings. It involves an experimental phase to collect data on real buildings before and after renovation, followed by numerical modelling of selected case studies. A modelling strategy is proposed for simply but accurately modelling infilled reinforced concrete frame buildings, and sensitivity-based model updating is then performed to ensure fidelity to experimental observations. The calibrated models are used to analyse a wider range of cases, aiming to draw general conclusions about the effects of renovation works of infills on the overall building dynamics. They are also used for assessing the damageability of buildings in the presence of low and moderate seismic actions. Results of the experimental phase demonstrate that combined seismic and energy related renovations generally lead to an increase of the building frequencies. Simplified closed-form formulae providing an estimation of the frequency increase are provided as a function of the building geometrical features.