Masonry buildings in Italy represent the majority of the historical and cultural heritage and they very often represent the result of an unbridled urban growth, due to the need to fill all the possible urban spaces. For this reason, aggregate masonry buildings have been generated over the years, allowing the aggregation of different inhomogeneous structural units, interacting under seismic action. The present work is focused on the study of unreinforced masonry aggregates in row, considering structural units along the aggregate with geometrical differences each other, generated starting from the medium values of the variables used to study masonry aggregates with identical structural units in row. Once some distributions of those variables were defined, a set of aggregations of different structural units in row is generated, following the rules of the Response Surface (RS) statistical method, based on the definition of a statistical model expressing a response parameter (for instance the spectral acceleration corresponding to the attainment of the Life Safety Limit State) as a function of a set of variables. The RS model is calibrated through numerical data obtained by non-linear static analyses, with reference to buildings whose geometrical and mechanical properties are varied in prescribed distributions. A group of registered accelerograms was used to consider the variability of the seismic action, for defined ranges of magnitude and epicenter distances referred to the considered earthquakes. Finally, the data obtained from the simulations were used to plot the fragility curves, by applying full Monte Carlo simulations, in order to obtain the conditional probability of failure for different values of the peak ground accelerations (PGAC). The results showed considerable differences in the fragility if different directions of the seismic action are considered, due to the geometrical properties and the arrangement of the resisting masonry walls of the aggregate and to the torsional effects deriving from the aggregation of structural units in row. Moreover, the various structural units along the aggregate exhibit different seismic fragility, according to their position in the masonry aggregate in row.
Lidia Battaglia, N.B. (2020). Seismic fragility assessment of unreinforced masonry aggregate buildings in row.
Seismic fragility assessment of unreinforced masonry aggregate buildings in row
Lidia Battaglia
;Nicola Buratti;Marco Savoia
2020
Abstract
Masonry buildings in Italy represent the majority of the historical and cultural heritage and they very often represent the result of an unbridled urban growth, due to the need to fill all the possible urban spaces. For this reason, aggregate masonry buildings have been generated over the years, allowing the aggregation of different inhomogeneous structural units, interacting under seismic action. The present work is focused on the study of unreinforced masonry aggregates in row, considering structural units along the aggregate with geometrical differences each other, generated starting from the medium values of the variables used to study masonry aggregates with identical structural units in row. Once some distributions of those variables were defined, a set of aggregations of different structural units in row is generated, following the rules of the Response Surface (RS) statistical method, based on the definition of a statistical model expressing a response parameter (for instance the spectral acceleration corresponding to the attainment of the Life Safety Limit State) as a function of a set of variables. The RS model is calibrated through numerical data obtained by non-linear static analyses, with reference to buildings whose geometrical and mechanical properties are varied in prescribed distributions. A group of registered accelerograms was used to consider the variability of the seismic action, for defined ranges of magnitude and epicenter distances referred to the considered earthquakes. Finally, the data obtained from the simulations were used to plot the fragility curves, by applying full Monte Carlo simulations, in order to obtain the conditional probability of failure for different values of the peak ground accelerations (PGAC). The results showed considerable differences in the fragility if different directions of the seismic action are considered, due to the geometrical properties and the arrangement of the resisting masonry walls of the aggregate and to the torsional effects deriving from the aggregation of structural units in row. Moreover, the various structural units along the aggregate exhibit different seismic fragility, according to their position in the masonry aggregate in row.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.