Seismic risk assessment of unreinforced masonry buildings at a territorial scale: Fid-Bau Portal

Seismic risk assessment of unreinforced masonry buildings at a territorial scale

Muñoz Barrantes, Jorge

Masonry constructions represent a significant portion of building stocks in many seismic regions around the world. The seismic response depends on the singularities of construction techniques and materials. The building vulnerability categorization by the European macroseismic scale (EMS-98) states that the unreinforced masonry (URM) typologies present the greatest seismic vulnerability. The seismic assessment of unreinforced masonry structures is a complex task. The complexity arises due to the material particularities, construction techniques and loading variability characteristics. Modeling these uncertainties has a significant influence on the estimation of the global behavior of a masonry building. In order to evaluate the uncertainties in seismic analyses of URM constructions, the SAUMAC methodology is proposed. In SAUMAC, results (structural risk and fragility curves) are obtained from a synthetically generated building population associated to a specific building typology. In other words, it is creating results to a particular condition (theoretical building archetype) from the behavior observed in a building population of similar structural conditions. Monte Carlo simulations, computed by means of a MATLAB code, are used for obtaining the storey resistance and the architectural parameters. Once the parameters are founded, fragilities are constructed by solving the limit state equation (resistance > seismic demand) for incremental seismic intensities. The structural risk is calculated by the convolution of the seismic hazard curve and the structure fragility function. The acquired structural risk is then evaluated, based on the likelihood of a situation and the analysis of target reliability values presented in bibliography. The SAUMAC methodology results are compared with the damage statistics gathered at Castelnuovo town after the L’Aquila earthquake (2009).