Seismic loss estimation due to masonry infills in reinforced concrete buildings

Earthquakes occurred in the last twenty years in Mediterranean area had a significant impact at economic and social level. A significant part of economic losses for RC frames was due to damage to non-structural components, particularly to masonry infills and partitions. Therefore, the seismic behaviour of masonry infills should be reliably characterized through a correct definition of their displacement capacity at different damage states (DSs), and of the required repair activities after an earthquake with their relative costs, to improve the seismic damage assessment and loss evaluation for infilled RC frames. Therefore, the main goals of this study for a more reliable loss estimation are: (i) the analysis of the displacement capacity at given DSs aiming at the definition of drift-based fragility functions; and (ii) the analysis of direct losses due to damage to infills after seismic events. First, an extensive database of experimental tests on RC frames infilled with clay bricks or concrete blocks is collected. By means of the collected experimental results, drift-based fragility curves are defined, explicitly depending on infill brick materials. The influence of openings on displacement capacities is also evaluated. Finally, seismic losses related to infills are computed, providing expected monetary loss, also in this case depending on the infill typology. All the required repairing activities are listed and their cost are computed. Loss functions directly depending on IDR demand are finally provided for all the investigated infill typologies, thus fusing together damage and loss analysis for a simpler practice-oriented loss calculation.