Restoration Techniques Applied to Tile Dome Conservation in the Western Mediterranean. Valencia,Spain

The domes studied, widespread in a large area of the Mediterranean, constitute an architectural heritage of great value to the history of architecture and construction. They were all built using brick masonry and ceramic tile roofs. Restoration work has made it possible to define their geometry, including the construction layouts of the buildings. In addition, on inspection it can be seen that common construction problems tend to be located at specific critical points. The restoration process of different cases sharing the same methodology, construction criteria, and solutions is accurately described. Following international charters, there is minimal intervention and maximum respect for the original solutions, but also a carefully considered incorporation of new materials and technologies to improve the critical points.     

Seismic performance of historical vaulted adobe constructions: a numerical case study from Yazd,Iran

Past earthquakes have demonstrated that historical vaulted adobe buildings are highly vulnerable to seismic actions. Hence, it is crucial for such building typologies to be evaluated in terms of seismic capacity. To this end, this article deals with the seismic performance of historical vaulted adobe houses from the city of Yazd, Iran as one of the seismically active areas of the world and possessing a very rich adobe heritage. Thus, and based on a detailed geometrical survey, a representative sample of adobe houses from Yazd was studied using a simplified in-plane analysis based on three geometric indexes. Concerning the out-of-plane behavior, a deeper assessment was conducted by performing a numerical study, where the main influential parameters on the seismic behavior of vaulted adobe buildings were considered. The numerical analyses were carried out by adopting the limit analysis theory implemented in the Block2D software. The results obtained indicate the safe in-plane behavior of most of the houses and the safe out-of-plane response of the sample under gravitational loads. However, the sample out-of-plane safety under earthquake-induced loads seems to be a matter of concern.     

Reconstruction of the Rib Vaults of the Hypostyle Hall in the Maniace Castle of Siracusa After the 1693 Earthquake

Built in the first half of the 13th century on behalf of the Emperor Frederick II, the Maniace Castle of Siracusa focuses its enigma in the hypostyle hall (which was composed of 25 quadripartite rib vaults) and the design criteria adopted for its implementation. Recent research and a careful rereading of the documentary “restoration project” after the earthquake of 1693 have offered new tools to understand the construction techniques and building procedures for the entire organism. It has been possible to demonstrate that the different material (white limestone and volcanic stone) used for the vaults is, in fact, a product of reconstruction. The constructive node, which historiography has taken for granted, is now crucial—the documentary evidence of the restoration after the earthquake compared with the materials found in situ provide interpretive keys to decode genesis and procedures of the huge structure built five centuries before.     

Rodrigo Gil de Hontañón and 16th-Century Building Techniques: The Cimborio Vault of Archbishop Fonseca College Chapel in Salamanca (Spain)

Rodrigo Gil is one of the greatest masters of Spanish architecture. His brilliant career is partially explained by the efficiency of his design methods and his building techniques, especially evident in his ribbed vaults. If we examine the latter as a whole, the first aspect to be noted is undoubtedly their great formal complexity. However, the detailed study discloses that rather limited geometric and building techniques are hidden behind those elaborated patterns, aimed at simplifying and making the execution more economical. In order to bring some of these devices to light, one of his best-known vaults was selected for an in-depth study. The construction of a large-scale model of it also revealed some interesting features regarding the placing of the centerings and shorings during the erection.     

In-Situ Destructive Testing of Ancient Strengthened Masonry Vaults

ABSTRCT

Developing suitable tools to assess the actual structural performance and designing and executing interventions to improve that performance is a key issue in the field of conservation and enhancement of architectural heritage. This article presents the results of five full-scale destructive tests performed on the Castello di San Pietro in Verona (North-East Italy), a building set on a hill above the city and going back to the 19th century under the Habsburg Empire. It evaluates the behavior of the barrel vaults of 5.6 m span, 1.1 m rise, and 27 cm thickness in the original building. Although experimental work is common in the relevant literature, the testing program described here was not performed on reconstructed vaults but on original elements, which can reveal their real behavior more clearly. Four strengthening solutions were also evaluated, in which organic and inorganic fibers were applied to both types of matrix.     

Minimum Thrust of Rounded Cross Vaults

This study analyzes the static behavior of the rounded cross vaults based on the limit analysis approach developed for masonry structures and adopts a rigid no-tension constitutive model with no sliding. The kinematic theorem of the limit analysis with a compatible tridimensional mechanism is applied on these structures with the aim of evaluating the minimum thrust. In this way it was possible to build some abaci in which the ratio between the minimum thrust and the weight is plotted versus the geometrical characteristics of the vaults. Finally, the proposed abaci are used to calculate the thrust of the main vault of the Diocletian Baths in Rome.     

Cathedral of Milan: Structural History of the Load-Bearing System

The structure of the Cathedral of Milan is studied. The features of the building and the original aspects of its load-bearing system are discussed. The progressive development of the structural system is described following its historical phases through four centuries. The final configuration is then analyzed with its main load paths. Detailed information, collected during the 20th century restoration work, was used to determine the geometry and loads. Preliminary analyses are based on equilibrium principles, within the framework of limit analysis for masonry constructions. The main structural restoration works taking place during the life of the Cathedral of Milan are outlined. The results provide a basis for the verification of more detailed numerical analyses and a reference for restoration interventions. Furthermore, the introductory analyses presented here develop the knowledge for future studies devoted to the Cathedral of Milan, encompassing structural, construction, and architectural issues.     

Historic Barrel Vaults Undergoing Differential Settlements

ABSTRACT

A principal reason of damage in historic masonry vaults consists in relative displacements of the vaults’ abutments. Excluding the case of seismic-induced damage, cracks are often produced by differential settlements generated by the lateral wall instability or soil degradation (e.g., due to stress concentrations, non-uniform soil stratigraphy, flooding phenomena etc.). When dealing with historic vaults, the effects of long-term deformation processes cannot often be linked directly to causes, which may also be unknown. In this article, the effects of differential settlements on historic masonry barrel vaults are investigated. An efficient 3D contact-based model was developed to reproduce experiments on a scaled pointed barrel vault (representative of a typology of late-medieval barrel vaults in Scotland) under non-uniform differential settlement. First, the numerical model is used to simulate the experimental campaign, achieving good agreement in terms of crack pattern (longitudinal shear) and transverse-longitudinal deformation profiles. Then, further analyses are carried out to gain insight on the effects of several plausible uniform and non-uniform settlement patterns on representative historic barrel vaults. Various settlement configurations were analysed and complex failure patterns observed. This study could help analysts in understanding the nature of on-going deformation process in historic masonry vaults and engineers in the design of strengthening strategies.