The seismic risk assessment of existing masonry infilled reinforced concrete (RC) building portfolios is a highly relevant issue in Italy and other Mediterranean countries, particularly in regions where a large part of the built environment was not designed according to modern seismic codes. In the past, masonry infills were generally considered as non-structural elements hence not accounted for in the design process, whereas the results of experimental tests and past earthquake evidence have demonstrated how they strongly influence the global and local behavior of RC buildings. This paper addresses the characterization of the large-scale seismic performance of different types of masonry infilled existing buildings, with a particular focus on the uncertainty surrounding the definition of the properties and modelling of the masonry infills. To accomplish this goal, the study starts with the development of a fully integrated building stock, based on statistical data, and representative of masonry infilled RC buildings designed according to the Italian codes in force between 1960 and 1980, using a simulated design approach. The main typologies of masonry infill used in Italy, which are affected by significant dispersion, were considered in terms of material properties, thickness, presence of openings and manufacturing techniques. Statistical data and the results of experimental tests carried out on RC infilled frames were used to identify the main masonry infill typologies. Detailed numerical models able to predict the features of the RC frames were defined and assessed through the results of cyclic experimental tests available in the literature. Moreover, different numerical models to define the backbone hysteresis of masonry infills have been adopted to further characterize the uncertainties surrounding the infills. Finally, the impact of the observed uncertainty on the seismic vulnerability of the developed RC building portfolio has been assessed in terms of maximum base shear capacity.
Seismic assessment of masonry infilled RC building portfolio accounting for variability of infill properties
Daniele Perrone;
2020-01-01
Abstract
The seismic risk assessment of existing masonry infilled reinforced concrete (RC) building portfolios is a highly relevant issue in Italy and other Mediterranean countries, particularly in regions where a large part of the built environment was not designed according to modern seismic codes. In the past, masonry infills were generally considered as non-structural elements hence not accounted for in the design process, whereas the results of experimental tests and past earthquake evidence have demonstrated how they strongly influence the global and local behavior of RC buildings. This paper addresses the characterization of the large-scale seismic performance of different types of masonry infilled existing buildings, with a particular focus on the uncertainty surrounding the definition of the properties and modelling of the masonry infills. To accomplish this goal, the study starts with the development of a fully integrated building stock, based on statistical data, and representative of masonry infilled RC buildings designed according to the Italian codes in force between 1960 and 1980, using a simulated design approach. The main typologies of masonry infill used in Italy, which are affected by significant dispersion, were considered in terms of material properties, thickness, presence of openings and manufacturing techniques. Statistical data and the results of experimental tests carried out on RC infilled frames were used to identify the main masonry infill typologies. Detailed numerical models able to predict the features of the RC frames were defined and assessed through the results of cyclic experimental tests available in the literature. Moreover, different numerical models to define the backbone hysteresis of masonry infills have been adopted to further characterize the uncertainties surrounding the infills. Finally, the impact of the observed uncertainty on the seismic vulnerability of the developed RC building portfolio has been assessed in terms of maximum base shear capacity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
