Seismic Damage Assessment for RC Buildings from SHM Data

In long-term structural health monitoring (SHM), one of the main challenges is to correlate an observed variation in dynamic properties of a structure (i.e., fundamental periods, mode shapes, etc.) to a certain damage level. This correlation is fundamental for an instantaneous damage quantification that can trigger an alert for maintenance works, in the case of minor damage, or for immediate evacuation to protect the life of occupants in the case of a heavy damage. This paper focuses on seismic damage assessment, and adopts a methodology proposed by the authors to quantify the damage experienced in a building from SHM data through numerical analyses. A dataset of 3D existing reinforced concrete buildings representative of structures designed according to non-seismic standards in the Mediterranean region has been selected as a case-study, and non-linear dynamics analyses have been carried out to estimate global damage levels. Modal analyses are performed before and after the dynamic analyses to catch the variation in dynamic properties due to seismic damage. The probability of variation of the fundamental frequency of the structures are assessed for different damage levels.