The remarkable antique wooden umbrella structure embedded within the double dome of the Cathedral of Naples astonishes with its complexity and grandeur. Over the past decade, eminent scholars have investigated this structure; however, the authors believe that it warrants an additional perspective – an interdisciplinary approach that integrates the complexity of graphic representation with structural assessment – to understand better the purpose behind the construction of such an extraordinary and uncommon element within Neapolitan Baroque masonry domes. This study aims to analyse the dome as a unified system by employing a combination of methodologies, including limit analysis and the study of reticular wooden structures. The theoretical framework considers the principles governing masonry structures (modelled as no-tension materials) and timbre elements analysed through elastic theory. The focus is on defining the interaction between these two structural systems, building upon Heyman’s theories on curved masonry structures. The combination of these distinct materials results in a structurally complex and inhomogeneous system, revealing the rationale behind creating a ‘forest’ of solid chestnut wood. To fully comprehend the function of the entire structure, it is crucial to recognise that the timbre framework supports the upper dome without imposing additional loads on the lower one. This design was conceived to ensure the stability of the elliptical upper dome. The research investigates the structural and functional imperatives that led engineers to device such a sophisticated system in a highly challenging environment. Furthermore, it examines the changes in the structural behaviour of the current system compared to the original design, which did not account for the presence of the wooden structure.

Wood can represent a valid and important alternative to the most commonly used structural materials for the restoration of masonry buildings, with a view to efficient, effective and "conscious" renovation. Today, the modern technologies allows to overcome the structural limits of solid wood due to its own anisotropy. The use of composite wood elements makes possible to obtain excellent mechanical performances that consent to evaluate aspects such as the use of low environmental impact retrofit strategies. The aim of this work is the analysis of mechanical parameters related to CLT (cross laminated timber) panels in order to determine their possible use in the structural restoration of masonry buildings. The CLT panels consist of solid wood planks superimposed so that each layer has the fibres rotated ninety degrees with respect to the adjacent layer. The layers (always in odd number and at least three) can be connected by discrete joints, pins and nails, or glued together. This configuration enables to product large structural elements with considerable thickness. Two different experimental test campaigns were carried out on samples of panels with three and five glued layers. The purpose of experimentation activities was to evaluate the bending deformation of the wooden elements and shear strength of the bonding sections. All the tests were processed according to the provisions contained in the UNI standards. The test results were then compared with different theoretical calculation models to determine the one that best represents the tested material. The tests outcomes have shown that some characteristics of the material, such as the remarkable ductility, open different scenarios of use for the CLT panels in the field of structural restoration of masonry buildings.

The aim of this research is the structural study of the dome of Tesoro di San Gennaro in Naples compared with the more recent studies about San Francesco di Paola, as examples, respectively, of baroque and neoclassic style, emblems of different stylistic periods of Neapolitan architectural schools about domes and churches. The studies are carried out with particular attention to evaluating their seismic safety without considering the role of the vertical supporting structures. The analysis adopts graphical approaches to assess the safety of the two domes under vertical and horizontal loads, with a special focus on the effects of earthquakes. In the case of San Gennaro, the approach is mixed between the rigid-kinematic theory and the theory of elasticity due to the presence of a wooden structure, while in the case of San Francesco di Paola, only the thrust-line method was used, applying it to the three-dimensional structures through the slicing technique. In conclusion, the methods to assess the safety of the domes under both vertical and horizontal seismic loads allow for a comparison of the two structures and provide a comprehensive evaluation of their structural integrity. The study demonstrates, through a predominantly graphical methodology, the effectiveness of traditional equilibrium-based approaches in assessing dome stability, highlighting the active contribution of the timber structure in San Gennaro and quantifying its role under seismic loading scenarios.