Seismic vulnerability of unreinforced masonry buildings in Barcelona

Abstract

The development of the district of the Eixample started in 1860. During 90 years of construction, the model that gives the characteristic layout to the district was perfected. As a result of this process, the Eixample district is the most representative one of the city of Barcelona. The district of the Eixample is a densely populated area where nearly 70% of its buildings have a structural system that consists of unreinforced masonry bearing walls, a system that have been demonstrated to be structurally vulnerable in case of seismic hazard. In this study, a seismic analysis is performed on a building that represents well the typology found in the district. The selected building corresponds to the ones located at the sides of the square blocks that conform the district. The N2 capacity spectrum method (Fajfar, 2000) recommended by the European Normative Eurocode 8 is used in this study to evaluate the seismic vulnerability of the typical unreinforced masonry buildings of the Eixample district. In this project the pushover or capacity curve is determined by 3Muri, a software working under the FME method (Frame by Macro Elements) which have been developed by the University of Genoa. The seismic hazard is characterized by the demand spectra formulated by the Eurocode 8, the Spanish normative NCSE--‐02 and by demand spectra developed for the city of Barcelona by Irizarry (2004) using probabilistic and deterministic approaches. The results of the analysis indicate that the damage scenarios differ substantially when applying the mentioned demand spectres. The Spanish norm, as well as the Eurocode 8 demand spectra, have been demonstrated to be less demanding than both probabilistic and deterministic approaches developed by Irizarry. The study highlights the non--‐negligible seismic risk of the masonry buildings.