Georadar investigations in the central nave of Hagia Sofia,Istanbul (Turkey)

Within an interdisciplinary project to study Istanbul’s Hagia Sofia, a georadar survey was carried out in the central nave to assess if the deformations of the structure previously observed could be related to a differential behavior of the subsoil caused by architectural remains underneath. This study faces an unusual challenge since it was necessary to study the space beneath the scaffolding placed for the restoration works. The survey of the central nave was successful and allowed the detection of remains of walls that probably formed the basement of a previous 18- by 22-m structure. In addition, another interesting feature was discovered 2 m below the marble mosaic in the southeastern part of the nave. Although it is not possible to define its function, it seems that there could be a close relationship between this 2- by 3-m buried structure and the marble mosaic in the floor surface. Although some structures were identified under the floor of Hagia Sofia, there are no major changes in the topography of the central nave floor.     

Historical mortars dating from OSL signals of fine grain fraction enriched in quartz

In the last years the mortar dating through Optically Stimulated Luminescence (OSL) techniques has become a viable support for chronological estimations (date of construction or restoration episodes) of historical buildings. However, the dating of mortar has still open issues mainly regarding the assessment of the bleaching degree of quartz, the analysis of the OSL processes for this type of samples and the need to do appropriate tests for the most correct evaluation of the equivalent dose. This paper discusses the results obtained by OSL dating (blue diode stimulation) on the polymineral fine grain phase, enriched in quartz, extracted from lime mortar samples collected from different sites. Thermal transfer effects, through the behaviour of Equivalent Dose (ED) and recovery tests, degree and time of bleaching were studied. For each mortar sample the adjacent brick was collected; in some cases, sampling of the bricks bracketing a mortar layer was a possibility, thus obtaining a direct comparison with the standard thermoluminescence (TL) dating on the bricks. The results obtained show, for this set of samples, the possibility of dating the mortars through the use of the fine grain fraction provided of a suitable chemical-physical preparation procedure and the verification of the bleaching conditions.     

Different approaches to date bricks from historical buildings

The application of Thermally (TL) and Optically (OSL) Stimulated Luminescence on bricks used as building material has allowed solving an chronological issue in the field of historical building dating. The possibility to use one or more methodologies of dating is closely related to the luminescent and granulometric characteristics of the sample. Using some brick samples collected in the church of Sain Seurin in Bordeaux (France), this paper discusses the implications and the possibility to use different approaches and techniques for dating. With this aim luminescence measurements were performed on both polymineral fine grain and quartz inclusion phases extracted from each brick. For Equivalent Dose (ED) and consequently age determination, TL on mixed fine grain fraction (FG), OSL on quartz inclusions (QI) and on mixed fine grain (FG*) fraction, were used. The results obtained suggest the advantage of using OSL technique on fine grain fraction cleaned up by IR stimulation (FG*), but the use of quartz inclusion represents indeed a good alternative.     

New compositional data on ancient mortars from Hagia Sophia (Istanbul,Turkey)

This study shows the results of a multidisciplinary collaboration between the University of Calabria (Italy) and the National Autonomous University of Mexico (UNAM), about the compositional characterization of some mortars taken from Hagia Sophia in Istanbul (Turkey), one of the most important buildings in antiquity. Twenty samples of joint mortars were analysed by micro-chemical analyses (SEM-EDS), X-ray powder diffraction (XRPD), optical microscopy (OM) and transmission electron microscopy (TEM). The compositional study allowed us to define, with more detail, the construction phases of the fifth, sixth and tenth century. The petrographic analysis in thin section by optical microscopy showed four typologies of sands, used as aggregate, with specific compositional features. SEM-EDS analyses and TEM observations of the binder around the ceramic fragments of the aggregate showed the presence of different morphologies of single C-S-H compounds.     

Pier Paolo Pasolini and the medium of song: Texts written for Laura Betti for the Giro a vuoto show

This article focuses on the outcome of an important episode within contemporary Italian culture: the encounter between the world of literature and song, and specifically examines the lyrics written by Pier Paolo Pasolini for the actress and singer Laura Betti for the Giro a Vuoto show, performed in 1960 in Milan. This essay intends to highlight the key elements of this encounter and the characteristic elements of these songs by virtue of textual and stylistic analysis, and provide remarks with regard to the relationship between music, text and singing performance. A study of this kind allows emphasis to be placed on the innovation originating from this distinctive collaboration which represents an important sign of change towards the emergence of a quality song within the mass market which would later come to be defined as canzone d’autore (singer-songwriter genre).     

Seismic refraction tomography surveys as a method for voids detection: an application to the archaeological park of Cava Ispica,Sicily, Italy

Geophysical surveys are commonly used in areas where the presence of ancient civilizations is historically documented. These investigations are able to detect through indirect methods the presence of bodies or structures in the subsoil measuring the variations of some physical parameters, obtaining information about archaeological remains without causing harm to them.

In the present study, we investigated the presence of anthropogenic buried cavities partially filled with rubble material, in an area located in the northern part of Cava Ispica, one of the most important archaeological sites located in south-eastern Sicily. The results of seismic refraction prospections, processed with tomographic methods, are presented and discussed. The entire valley contains prehistoric burial sites, Christian catacombs and residential units of various kinds. Despite the numerous searches made over past years, much still remains to be discovered.

The seismic refraction tomographic data, analyzed in 3D, revealed the presence of low velocity values (<400 m/s) areas that, considering the lithotypes locally present and the features of other archaeological structures discovered during previous surveys, can be ascribed to the presence of possible cavities. The obtained results show how such geophysical inspections represent an important preliminary tool for archaeological surveys.     

Characterisation of archaeological mortars and plasters from kyme (Turkey)

The present study focuses on the compositional characterisation of Roman, proto-Byzantine and Medieval mortars, sampled in the archaeological site of Kyme (Turkey), an Aeolian city, founded in the middle of the XI century BC by Greek populations. The mortars were studied through elemental (SEM-EDS, XRF), mineralogical (XRPD, De Astis calcimeter) and petrographic (polarised optical microscopy) analysis. The comparison between the samples allowed us to emphasise compositional differences within mortars of the same historical period.In particular, we detected the prevalent use of cocciopesto, which was used as a pozzolanic additive to create hydraulic mortars in the Roman and Byzantine period. The cocciopesto was used to improve the technological properties of an initially slaked lime. Furthermore, compositional similarities allowed us to attribute an unknown sample to the Roman period. Our study also pointed out the fact that the lower quality mortars belonged to the Medieval period. As a matter of fact, the most friable sample belonging to the Middle Ages turned out to be a mixture of clay, lime and volcanic sand.     

A Multidisciplinary Study on the Seismic Vulnerability of St. Agostino Church in Amatrice following the 2016 Seismic Sequence

ABSTRACT

The big earthquake of August 24, 2016 and subsequent major shocks severely damaged many historic villages in Central Italy and dramatically showed the intrinsic vulnerability of the diffused architectural heritage. The St. Agostino church is one of the collapsed historical buildings, being inside the epicentre village of Amatrice. During the long seismic earthquake swarm, progressively the church was damaged and monitored. This multidisciplinary study of the damage of the church includes correlations of all the data derived from three steps geomatics surveys (3D aerial and terrestrial models): the archival drawings and images documenting previous events distressing the building, the previous strengthening intervention, and finally the seismic site response analysis (from Amatrice’s accelerometric station). Through a back analysis carried out by a finite elements model, it was possible to understand the seismic vulnerability of this historical building, in relation to the previous interventions and damage events. The proposed methodology, based on the interdisciplinary data analysis, provides useful information for the next strengthening projects of damaged historical monument.