Vol.:(0123456789) Bulletin of Earthquake Engineering https://doi.org/10.1007/s10518-020-00831-1 1 3 ORIGINAL RESEARCH Seismic damage and fragility assessment of ancient masonry churches located in central Chile Nuria Chiara Palazzi 1,2,3  · Philomene Favier 4  · Luisa Rovero 1  · Cristián Sandoval 2  · Juan Carlos de la Llera 2,3 Received: 26 July 2019 / Accepted: 21 March 2020 © Springer Nature B.V. 2020 Abstract An assessment of damage and seismic fragility of historical unreinforced masonry churches located in Chile’s central valley was carried out employing the results of a feld survey of 106 ancient churches, after the 2010 Maule earthquake. The observed damage was cor- related with recurrent failure mechanisms of unreinforced masonry structures, by taking into account 22 local mechanisms involving macro-elements on these churches. The aver- age damage level sufered by each church was computed considering the global and local behaviors of the structures through a damage index computed as a weighted mean of the levels of damage observed for each mechanism. The results of this damage index method are used to obtain Probability Mass Functions and suitable probabilistic tools are used to propose Empirical Fragility Curves (EFCs) for these structures. The EFCs are directly usable by stakeholders involved in risk assessment aimed to the prioritization of possible future damage mitigation strategies and other decision making processes relative to this historical heritage. Keywords Fragility curves · Masonry churches · Heritage built · Seismic fragility assessment 1 Introduction Past earthquake surveying activities after the 2010 Maule earthquake (Mw 8.8), demon- strated that Chilean Built Heritage underwent extensive structural damage in particular, in unreinforced masonry (URM) churches (D’Ayala and Benzoni 2012; Palazzi et al. 2019a, * Nuria Chiara Palazzi nuriachiara.palazzi@cigiden.cl 1 Department of Architecture, University of Florence, Piazza Brunelleschi, 50121 Florence, 6, Italy 2 Department of Structural and Geotechnical Engineering, Pontifcia Universidad Católica de Chile, Santiago, Chile 3 National Research Center for Integrated Natural Disaster Management CIGIDEN, CONICYT/FONDAP/15110017, Santiago, Chile 4 University Grenoble Alpes, INRAE, 38402 Saint-Martin-d’Hères, LESSEM, France