Probabilistic seismic assessment of a high-rise URM building

Several European urban nuclei are constituted by a significant number of ancient structures that belong to constructive typologies in which the seismic demand was not considered in their design at the time. Both, the accurate definition of the mechanical properties of their materials, and a proper seismic demand, are two of the major difficulties in the seismic damage assessment of structures due to their respective large associated uncertainties and variability, respectively. A representative high-rise unreinforced masonry (URM) building of the Eixample district in the city of Barcelona (Spain) is taken as a case-study. The building is modelled as an isolated load-bearing walls system with unidirectional iron beams-brick vaults slabs. The seismic demand variability is addressed by means of different ground motion records, which were selected following the conditional spectrum procedure, and subsequently scaled to different levels of demand (pga) according to the incremental dynamic analysis methodology. On the other hand, and due to the lack of homogeneity and level of knowledge associated with the large diversity of manufacturing and construction techniques, the compressive strength, shear modulus, shear strength and Young modulus are chosen and modelled as random variables in order to encompass the material uncertainties. Sufficient and representative samples are selected from both the population of mechanical properties of materials and the population of incrementally scaled dynamic analyses. Results are categorized in accordance to each of the selected random variables and seismic demand inputs (record and/or pga), providing, in varying degrees, their different correlations and tendencies among them.Postprint (published version