Alberto Taliercio

Masonry buildings belonging to the architectural heritage are often characterized by the presence of masonry arches, vaults, and domes. A thorough structural assessment of masonry vaults is essential from a conservation perspective, as these elements are often subject to damage, cracks, and, in some cases, collapse. In the literature, the structural behaviour of the most common vault types has been extensively investigated using a broad blend of techniques capable of capturing significant aspects of the complex behaviour of masonry. However, for some less common vault typologies, a comprehensive understanding of their structural response remains an open issue. In this multifaceted context, the present contribution aims to investigate the structural behaviour of a distinctive type of vault, namely the umbrella vault, in which a series of webs are arranged in an umbrella-like configuration. To this end, an iconic case study is selected for its geometric complexity, namely the umbrella vault of Masegra Castle (northern Italy). Peculiar aspects are manifold, the most important being the irregularity of the quadrangular plan. The analysis focused on the structural response of the vault under self-weight, in the presence and absence of supporting walls. During the modelling phase, an interdisciplinary approach was adopted, integrating historical and diagnostic information. Starting from the available data, the study proposes nonlinear finite element analyses, discussing the most appropriate modelling strategies, based on solid or plate/shell finite elements, and performing sensitivity analyses on the mesh used and the vault thickness.

This study, framed within the context of the lower bound theorem of limit analysis, aims to assess the anti-funicular equilibrium of masonry arches and domes using a computational approach based on the constrained force density method. In contrast to the commonly adopted classical Heyman’s assumptions, the approach proposed here considers the effects of finite compressive strength in the material. Assuming a fixed plan projection for a network with independent sets of branches, a suitable set of local constraints is enforced at each joint to account for the limit bending moment resulting from the material’s assumptions, including limited compressive strength and zero tensile strength. Additionally, the stereotomy of the voussoirs is considered by assigning a geometric law to the joint inclination. The collapse load is determined by formulating a multi-constrained maximization problem. The method is validated using a modern version of the semi-analytical Durand-Claye’s method. For benchmark case studies, such as symmetric masonry arches and domes with specific stereotomies subjected to axi-symmetrical load conditions, the set of statically admissible solutions compatible with equilibrium and strength requirements is graphically determined in terms of the horizontal thrust and its eccentricity at the crown, examining the shape of the stability area. Assuming an infinite value for the friction coefficient, the collapse condition is reached when the stability area shrinks to a single point. The results obtained from both of these methods are in excellent agreement. The influence of compressive strength on the bearing capacity of the structures is also discussed.

The prediction of the macroscopic behaviour of Flemish bond brickwork (FBB) is dealt with. From the finite element analysis of a representative volume element (RVE) of masonry, assumed to be a hete...