Refurbishing, Strengthening and Retrofitting Façades to Increase Seismic Resistance

Recent events have shown that existing, older buildings often lack sufficient seismic resistance. Façade collapse is particularly concerning as falling components can cause personal injury and block escape and emergency access routes. The 2020 earthquakes in Croatia highlighted these issues and caused considerable damage to thousands of buildings, a high proportion of which were either old or poorly preserved and located in Zagreb’s historic centre. Due to the cultural importance of historic buildings, when restoring or improving the static load-bearing capacity, suitable and aesthetically sympathetic repair methods should be used. This paper presents methods for the repair of existing façades which can be used to preserve the historic building fabric and strengthen the façade structure with the aim of meeting seismic design requirements. An alternative to large shake table tests is described, the technical background is explained and test results are presented.