PROPOSAL OF A GENERAL METHODOLOGICAL APPROACH FOR THE SEISMIC ASSESSMENT OF HISTORICAL MASONRY AGGREGATES

The vulnerability of masonry aggregates has been highlighted by recent strong earthquakes. Most of the Italian historical centres are characterized by adjacent masonry structures connected in aggregate that have undergone to structural and functional changes over time. Their seismic vulnerability shall be studied to avoid disastrous outcomes. Many studies are available in the technical literature to identify the most vulnerable structures in historic centres from a macroscopic perspective, furthermore the seismic behaviour of some typical structures was studied in detail using sophisticated numerical methods to provide a specific seismic vulnerability assessment. However nowadays there is not a general and standard procedure available, mostly methodological, based on well-known analysis methods, that can be followed to evaluate the seismic vulnerability of any building aggregate, and that allows to identify effective retrofitting interventions. Moreover, common national regulations do not provide a standard procedure for practitioners to follow in such cases. Thus, the purpose of this contribution is to show a protocol to be used in common design, that has been developed in a wider work, and it is based on a broad blend of analyses that can be performed with low-cost software. With different hypotheses and modelling assumptions, numerical analyses range from simple eigenvalue simulations to full 3D pushover computations. The suggested method has been presented in a wider work where it has been applied and benchmarked to the ex-monastery of Santa Maria della Pace in Piacenza, Italy.