A hybrid approach for the seismic vulnerability assessment of the modern residential masonry buildings

In this paper a hybrid approach for the seismic vulnerability assessment of the existing modern masonry buildings is developed. The procedure takes advantage of the standardized designs and technological features of the XX century masonry structures to define a hybrid framework constituted by two different phases: an urban scale one and one at the building level. The methodology is applied at the external outskirt of the city of Florence, where the residential stock is characterized by a significant number of masonry constructions. At the urban level a cognitive research based on archive research and data collection allowed the identification of the architectural and structural features of modern masonry buildings. Then, a selected case study representative of a wider class is chosen for a probabilistic procedure based on nonlinear static analysis and targeted at the derivation of fragility curves. The analytical results have been assumed to calibrate a simplified procedure available in literature and targeted at the definition of bilinear capacity curves. The calibration of the different coefficients was conducted in terms of generic outcomes, defining correlations within architectural elements and their seismic behavior (facades, side walls). The rapid methodology has been finally implemented at the urban scale, and the results of the work exhibit a relevant vulnerability of existing buildings. The simplified methodology overcomes the limits of the empirical methodologies at the urban scale constituting a valid tool for the rapid seismic vulnerability assessment at urban scales of the modern masonry structures of different contexts.