DISCRETE MODELING OF HISTORICAL STONE MASONRY: THE CASE OF NURAGHE PALMAVERA

A discrete element method is proposed to investigate the structural behavior of ancient stone masonry heritage. The computational model is based on a hemivariational approach that enables the simulation of complex elasto-damage behavior and collapse mechanisms. Each discrete element is defined as an augmented stone, consisting of a rigid block with an equivalent interaction layer, with interactions modeled through springs governed by energy-based damage laws. The governing equations and damage criteria are derived by a hemivariational principle, while an explicit-staggered integration scheme is employed to simulate the evolution of deformation, cracking, and progressive collapse. The proposed methodology is particularly suited to address the challenges of historical stone masonry, which is often characterized by irregular geometry, material heterogeneity, and long-term degradation. By combining physical modeling with numerical simulation, the framework provides insight into both global stability and localized damage phenomena that are essential to understanding structural vulnerability. To demonstrate its applicability, the framework is applied to the real case of Nuraghe Palmavera, a Bronze Age masonry monument of great archaeological and cultural significance in Sardinia (Italy). The results reproduce overall stability features as well as possible localized damage patterns, thereby validating the ability of the discrete element approach to capture realistic structural behavior. Beyond methodological advances, this study highlights the role of physics-based simulations in the preservation of architectural heritage, offering valuable support for conservation planning, risk assessment, and the long-term safeguarding of vulnerable masonry monuments.