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Tesis:

Seismic vulnerability of buildings and non-structural elements: insights from the 2011 Lorca earthquake

  • Autor: NAVAS SÁNCHEZ, Laura Araceli

  • Título: Seismic vulnerability of buildings and non-structural elements: insights from the 2011 Lorca earthquake

  • Fecha: 2023

  • Materia:

  • Escuela: E.T.S. DE ARQUITECTURA

  • Departamentos: ESTRUCTURAS Y FISICA DE EDIFICACION

  • Acceso electrónico: https://oa.upm.es/76302/

  • Director/a 1º: CERVERA BRAVO, Jaime
  • Director/a 2º: SAVOIA, Marco
  • Director/a 3º: FERRETTI, Francesca

  • Resumen: This Thesis presents a profound study of the vulnerability of buildings and non-structural elements stemmed from the investigation of the Lorca 2011 earthquake. This moderate magnitude seism, Mw 5.2, constitutes one of the most significant earthquakes in Spain in recent decades, as it left nine fatalities due to falling debris from reinforced concrete buildings, 394 injured and material damage valued at 800 million euros. Within this framework, the most relevant international and national initiatives and projects concerning the vulnerability assessment of buildings within the context of seismic risk studies have been presented. Besides, the exposure of the city has been analysed and the knowledge about the different typologies expanded. Said studies have revealed two lines of research for this work. Firstly, the existence of a gap in the literature, the lack of a rational method to determine the adequacy of a specific fragility curve for the particular seismic risk study of a region. Secondly, the relevance of advancing in a field still under underdevelopment, that related to the seismic performance of non-structural elements such as masonry parapets and infill walls. As a consequence, on the one hand, a method to assess and select fragility curves for seismic risk studies from the catalogue of those available in the literature has been elaborated and calibrated by means of a case study. The said methodology is based on a multidimensional index and provides a ranking that classifies the curves assessed in terms of technical suitability, suitability for the local system and building class similarity with the typology object of study. The results of its application to the case of Lorca indicate the adequacy of the fragility curves selected in previous studies is limited. With this outcome in mind, fragility curves for the typologies of unreinforced masonry buildings present in Lorca have been elaborated using actual buildings of the region as samples and more updated methods. Moreover, a simplified method for accounting for the unpredictable directionality of the seism in the creation of fragility curves has been contributed. On the other hand, it has been studied the characterisation of the seismic capacity and demand of the non-structural elements that caused most of the human losses: unreinforced masonry parapets and exterior infill walls pertaining to four to six-storey infilled frame reinforced concrete structure buildings. Concerning the capacity, an analytical approach derived from theoretical considerations to characterise the complete out-of-plane seismic response curve of unreinforced masonry cantilever walls has been provided; as well as a simplified and more practical trilinear version of it. Concerning the demand, a number of methods for characterising the Floor Response Spectra of the reinforced concrete buildings present in the area have been tested by means of case studies. The results of the analyses conducted have led to the recommendation of the implementation of the methodologies already included in the Italian regulation, NTC18, in the upcoming Spanish regulation, NCSR22. Finally, some future lines of investigation related to ways of combining the advances in exposure and vulnerability when performing seismic risk studies are exposed.