Seismic performance of masonry residential buildings in Lorca's city centre, after the 11th May 2011 earthquake

Abstract

[EN] Lorca May 11, 2011 earthquake, whose magnitude and intensity reached Mw=5.1 and I=VII, caused heavy damages, showing the vulnerability of masonry historic buildings and reinforced concrete improper designed structures. The main objectives of this paper are to study the seismic response of unreinforced masonry residential building stock in Lorca historic centre and to compare it with the vulnerability and feasible collapse mechanisms predicted by the FaMIVE Method (D Ayala and Speranza in Proceedings of 12th European conference of earthquake engineering. Elsevier Science Limited, London, 2002; Earthq Spectra 19(3):479 509, 2003), which has been proved to be accurate in the description and prediction of damages in this type of structures. For this purpose, three onsite surveys were carried out, in May, June and December 2011, on a sample of the masonry residential buildings in Lorca historic centre (area included in the Special Protection and Rehabilitation Plan of the Historic and Artistic Site of Lorca). Information regarding geometry, quality of materials, structure and c nstruction characteristics was collected, establishing the observed collapse mechanisms and evaluating rigorously damage and crack patterns. Google Street View was used for the analysis of the state of the buildings before the earthquake. These buildings were then assessed and mapped using a GIS system. Results provided good accordance with the observed data, showing, at the same time, very different building seismic performance. Effective connections between façades and party walls, a good maintenance level of masonry and roofs and the use of specific reinforcement elements have proved to be relevant factors in lowering the vulnerability and improving the seismic behaviour of unreinforced masonry structures in Lorca historic centre.