Structural analysis of the Dome of San Cerbone Cathedral in Massa Marittima (Italy)

Angelini G., De Falco A., Pellegrini D.

Masonry dome  Non-linear elasticity  Masonry-like material  Numerical methods  J.2 PHYSICAL SCIENCES AND ENGINEERING 

In this paper the assessment of the dome of the medieval cathedral of Massa Marittima (Italy) is carried out in order to evaluate the causes of its heavy damage. The deformation and the crack patterns on the vault and on the surface of the masonry drum are particularly complex and seem at first glance incomprehensible. In the context of the safety assessment of ancient masonry constructions, structural modeling can provide an important contribution to diagnose the damage while representing at the same time a valuable instrument to predict the effectiveness of consolidation interventions. This paper shows how the finite element numerical approach can be successfully employed as an assessment tool, provided that it is driven by the empirical intuitive method based on kinematic evaluations. The analysis has been conducted via the NOSA-ITACA code, developed in the framework of the project "NOSA-ITACA - Tools for modelling and assessing the structural behavior of ancient constructions" (2011-2013) promoted by the Tuscany Region (Italy). The code models masonry as a nonlinear elastic material, known as masonry-like (or no-tension) material, and is a code suitable to assess the structural behavior of masonry constructions. Initially, the different structural elements composing the dome were investigated to analyze their specific role and their typical pathology. The structure safety factor was successfully evaluated thanks to a detailed three-dimensional model of the dome with its substructure. Once validated the model in the light of the surveyed crack patterns, was also employed to design adequate strengthening interventions. For the sake of comparison, a commercial code was also used to perform the same analysis with a different constitutive equation for material thus offering the opportunity to highlight the peculiarity of NOSA-ITACA code.

Source: SAHC 2014 - 9th International Conference on Structural Analysis of Historical Constructions, Mexico City, 14-17 October 2014