Comparative Pushover and Limit Analysis During Seismic Events: A Case Study of a Masonry Structure in Southern Italy

Among historic masonry buildings, some might be constructed with different masonry materials for many reasons. Such buildings are characterized by various difficulties associated with the numerical modelling for structural behaviour evaluation purposes. This is evident since current standards do not provide sufficient explanation on the numerical modelling techniques, whilst they suggest using different methods without ensuring the required refinement of the model itself. The differences between the two masonry materials in terms of physical and mechanical properties of the “mixed” masonry buildings might provoke certain collapse mechanisms which are affected by the modelling techniques. In this paper, a typical case study was examined, a former cinema from the 1950s, built by a stone masonry for the lower part and a brick masonry for the upper one, with a concrete frame in between. In particular, a comparison is made between a traditional pushover, performed on a brick-element FE model with Mohr-Coulomb rupture criterion, while in the second case, a limit analysis was implemented on the same model, where the structure is discretized by means of infinitely rigid resistant triangle elements with plastic admissibility allowed only at the interface between the various elements, for a limit analysis of local kinematics. The present work aims to highlight the differences in the structural response resulting from the variant modelling methods by means of uncertainty sensitivity analysis, since the standards focus more on the analysis method rather than the modelling technique. Thus, the final objective of the work is uncertainty about the response estimate.