ABSTRACT
This chapter presents the procedure and findings of an experimental campaign oriented to characterize the modal properties of the Metropolitan Cathedral of Santiago de Chile. The dynamic characterization was carried out by 22 set-ups considering ambient vibrations. The evaluation of the structural performance of heritage masonry constructions has become a priority for some cities around the world seeking to preserve its architectural heritage. However, this assessment remains a complex task. A major difficulty is to obtain the mechanical properties of component materials, the current damage in the structure, and the degree of interaction between its various resistant elements. Because of these and other difficulties, some general recommendations for structural analysis of historical constructions have been proposed under a multidisciplinary approach. Several options of weighting factors were tested. According to M. I. Friswell & J. E. Mottershead, the confident that exists for low frequencies is greater than for high frequencies, thus decreasing trend li-near and parabolic relations were reviewed.
