Seismic vulnerability of structures: application to the Civil Protection building in Andorra

This works deals with the seismic vulnerability of buildings in the Pyrenees mountains region where almost a thousand earthquakes are recorded each year in the border area. The challenge is twofold: first to detect the damage due to seismic events and then to localize it inside studied buildings. Operational Modal Analysis (OMA) coupled with numerical modelling by Finite Element (FE) constitutes an interesting approach to address these issues. Here we intend to apply such methodology on a strategic building located in Andorre-la-Vieille whose structure is complex, irregular and heterogeneous. The structural behaviour of the building is studied through frequency computation method in order to identify its undamaged behaviour. A seismic event is next simulated by a non-linear dynamic computation method which creates damage within the structure. Numerical results (natural frequencies, modal shapes and damage location) allow highlighting damaged zones induced by the earthquake and quantify degradation level in these areas. Accordingly, some guidelines may be given in view of the future instrumentation of the building (accelerometers and RAR).