The relevant losses determined by recent earthquakes stressed the vulnerability of historical masonry constructions towards horizontal seismic actions, therefore highlighting the need for reliable approaches for the structural assessment and following retrofit. During the last decades, the scientific community has widely investigated the tools to analyse the performance of such structural typologies, resulting in a multitude of different methodologies depending on the building’s features and the goal of the analysis. The task is particularly challenging because of the frequently limited knowledge concerning the state of the art and the high structural complexity due to overlapped construction phases. A general literature review of the methods adopted for the structural assessment of historical masonry buildings is proposed in the present paper. The methods are grouped according to the operational scale, providing an overview of the current state of the art.

Historical buildings are characterized by a high level of complexity due to a long realization process often resulting in an overall lack of information and in a structural behavior that is more similar to a "structural aggregate" rather than to a "single building". The assessment of the static safety and seismic vulnerability then requires a multidisciplinary and multilevel approach including a deep and accurate preliminary knowledge phase before performing structural analyses. In the present paper, a consolidated knowledge-based procedure is presented and applied to four case studies in Italy. Interest is focused on the knowledge phase, combining critical-historical analysis to in situ architectural, geometrical, structural, material, and geotechnical aspects. The knowledge phase proves to be fundamental in understanding the structural behavior of cultural heritage, with special attention to the determination and analysis of local mechanisms and vulnerability elements and allowing to validate and give reason to numerical results.

No abstract

The present paper deals with the elaboration of a methodology to assess the macro-seismic risk of monumental historical buildings, representing a fundamental part of the European cultural assets. Monumental buildings typically arise from a very complex constructive and morphological evolution process characterised by modifications occurred over the centuries. Therefore, they are usually heterogeneous buildings similar to 'structural aggregates' rather than single constructions and characterised by a structural behaviour depending on the mutual interaction of different structural units. An accurate knowledge process can allow the determination of structural units within the complex: such units can be therefore analysed using a specific evaluation form conceived to provide a 'risk ranking' of the different portions constituting the aggregate and accounting for vulnerability, exposure and seismic hazard parameters. The proposed methodology exploits what is already used to quickly determine structural features and eventual damages in the post-earthquake phase for ordinary buildings, introducing specific aspects typical of historical-cultural heritage requiring attention. According to the results achieved, retrofit interventions or deepen investigations can be planned for units provided by a higher position in the risk scale, optimising and rationally planning the use of available economic and time resources. In the present work, the proposed methodology is applied to the monumental complex of the Certosa di Calci, Pisa (Italy).

No abstract