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Casula, Giuseppe
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Casula, Giuseppe
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giuseppe.casula@ingv.it
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staff
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7004905743
139 results
Now showing 1 - 10 of 139
- PublicationOpen AccessHigh Resolution 3D modelling of Cylinder shape bodies applied to 1000 ancient AD columns(EGU - Copernicus, 2020-05-08)
; ; ; ; ; ; ; ; ; A multi-technique high resolution 3D modelling is described here aimed at the investigation of the state of conservation of carbonate columns of the 1000 BC ancient church of Buon Camino located in the homonymous district of the town of Cagliari (Italy). The integrated application of different Non-Destructive Testing (NDT) diagnostic methods is of paramount importance to locate damaged parts of the building material of artefacts of historical buildings and to plan their restoration. In this study a multi-step procedure was applied starting with a high resolution 3D modelling performed with the aid of Structure from Motion (SfM) Photogrammetry and Terrestrial Laser Scanner (TLS) methodologies. For this delicate task we operated simultaneously a Nikon D-5300 digital Reflex 24.2 Mega pixel Camera and a Leica HDS-6200 Terrestrial Laser Scanner. Subsequently, starting from the information detected with the above methods deeper material diagnostics was performed by means of high resolution 3D ultrasonic tomography aimed at the capillary definition of the elastic properties in the inner parts of the building materials. Measurements of longitudinal wave velocity from ultrasonic data were performed using the transmission method, namely two piezoelectric transducers coupled on the opposite sides of the investigated columns. The ultrasonic data acquisition was planned designing an optimal survey and providing a very good spatial coverage of the investigated columns. The columns were then criss-crossed by a large number of ray paths forming a dense 3D net. The SIRT (Simultaneous Iterative Reconstruction Tomography) algorithm was used to produce the 3D rendering of the velocity distribution inside the investigated columns. With this method the damaged parts were located and it was possible to distinguish them from the unaltered areas. The information on the superficial material conditions obtained by SfM and TLS techniques were compared and integrated with the information of the inner materials obtained by 3D ultrasonic tomography. The results of the above non invasive geophysical techniques have been interpreted in the light of the different textural and petrophysical features of the study carbonate building materials. The study of the main textural features, such as the relationship between bioclasts, carbonate matrix, or that of the cement and petrophysical characteristics such as the nature and distribution of porosity were found to be of fundamental importance in the interpretation of the geophysical data (e.g. TLS reflectance and longitudinal acoustic wave propagation). Therefore a detailed analysis of the textures and pore microstructure were carried out from petrographic thin-sections in Optical and Scanning Electron Microscopy (OM/SEM). The final result of our multi-step-technique integrated methodology is a sophisticated 3D model with a high resolution 3D image representing the internal and external parts of the investigated columns in order to account for their static load resistance and possibly plan their conservation and restoration. The described procedure can also be applied to other cases in which a diagnosis is needed of the state of conservation of the variously shaped, layered-stones and composed artefacts typical of ancient historical buildings.91 16 - PublicationOpen AccessLinee guida per la programmazione remota e lo scarico dati di ricevitori GPS (Standard Trimble Navigation Limited - Serie 5000).(2006)
; ; ; ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Serpelloni, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Giovani, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; ; Nella fase di implementazione dell'hardware e del software per la materializzazione di stazioni GPS permanenti il problema della programmazione e scarico dati a distanza mediante modem da telefonia fissa, PSTN e ISDN o mediante modem da telefonia mobile, essenzialmente GSM /GPRS costituisce un problema di non facile soluzione. Anche laddove esista da parte delle aziende coinvolte nelle forniture un assistenza software che consenta di sviluppare dei prodotti personalizzati, alcune operazioni richieste vengono spesso eseguite dall'utenza con mezzi propri. Infatti, gli standard commerciali che vanno per la maggiore operano prevalentemente in ambiente Microsoft Windows e sono spesso privi della modularità e della flessibilità necessarie sia per adattarsi a problemi scientifici sia per la loro esecuzione in background in ambienti Unix (Linux, Solaris o HP-UX). In questo lavoro vengono analizzate le problematiche legate alla programmazione di ricevitori Trimble Navigation Limited modello 5700 CORS (Continuous Operating Reference Stations), in dotazione al Laboratorio di Geodesia e Telerilevamento dell'INGV-CNT, per un loro utilizzo nell’ambito di stazioni GPS permanenti. In particolare, è stato sviluppato un sistema automatico per il controllo a distanza, la programmazione e lo scarico dati di uno standard dei predetti ricevitori. Tutta la logistica della cascata hardware e dello strato software è stata sviluppata mediante strumenti da noi implementati; il risultato è sufficientemente stabile e può essere fattivamente utilizzato per il supporto alla realizzazione di stazioni permanenti GPS anche in siti dalla logistica scarsa come quelli situati in zone remote prive di linee telefoniche fisse e di alimentazione. Per il suddetto tipo di strumentazione infatti, non esiste in Italia una vera e propria assistenza Hardware e Software in grado di risolvere determinati problemi e, pertanto, in alcuni casi è stato necessario ricorrere sia al supporto tecnico dell'UNAVCO, il consorzio universitario Americano per il NAVSTAR GPS (http://www.unavco.org), sia alla nostra consolidata esperienza nel campo della strumentazione GPS. Il presente documento è rivolto ad un pubblico limitato costituito da quegli esperti del settore che siano interessati alla soluzione delle problematiche analizzate in questa sede.182 546 - PublicationOpen AccessAn innovative methodology for the non-destructive diagnosis of architectural elements of ancient historical buildings(2018-03-12)
; ; ; ; ; ; ; ; ; In the following we present a new non-invasive methodology aimed at the diagnosis of stone building materials used in historical buildings and architectural elements. This methodology consists of the integrated sequential application of in situ proximal sensing methodologies such as the 3D Terrestrial Laser Scanner for the 3D modelling of investigated objects together with laboratory and in situ non-invasive multi-techniques acoustic data, preceded by an accurate petrographical study of the investigated stone materials by optical and scanning electron microscopy. The increasing necessity to integrate different types of techniques in the safeguard of the Cultural Heritage is the result of the following two interdependent factors: 1) The diagnostic process on the building stone materials of monuments is increasingly focused on difficult targets in critical situations. In these cases, the diagnosis using only one type of non-invasive technique may not be sufficient to investigate the conservation status of the stone materials of the superficial and inner parts of the studied structures 2) Recent technological and scientific developments in the field of non-invasive diagnostic techniques for different types of materials favors and supports the acquisition, processing and interpretation of huge multidisciplinary datasets.962 88 - PublicationRestrictedA laser scanning-based method for fast estimation of seismic-induced building deformations(2013-02-28)
; ; ; ; ; ;Pesci, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Teza, G.; Dipartimento di Geoscienze, Università di Padova ;Bonali, E.; DAPT, Università di Bologna ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Boschi, E.; Dipartimento di Fisica, Università di Bologna; ; ; ; Monitoring damaged buildings in an area where an earthquake has occurred requires the use of techniques which provide rapid and safe measurements even in emergency conditions. In particular, remote sensing techniques like terrestrial laser scanning (TLS) can satisfy these requirements, since they produce very dense point clouds in little time and also allow an accurate geometric modeling of observed buildings. Nevertheless, strong constraints on TLS data acquisition geometry, such as acquisition distance and incidence angles, typically characterize an area in seismic emergency conditions. In order to correctly interpret the data, it is necessary to estimate errors affecting TLS measurements in these critical conditions. A reliable estimation can be achieved by means of experiments and numerical simulations aimed at quantifying a realistic noise level, with emphasis on reduction of artifacts due to data acquisition, registration and modeling. This paper proposes a data analysis strategy in which TLS-based morphological maps computed as point-to-primitive differences are created. The method can be easily used for accurate surveying in emergency conditions. In order to demonstrate the proposed method in very diverse situations, it was applied to rapidly detect deformation traces in the San Giacomo Roncole Campanile (Modena), the Asinelli tower (Bologna) and the Cantalovo Church (Verona), three buildings damaged by the Mw 5.9 Emilia Romagna 2012 earthquake (Italy). 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS) Published by Elsevier558 27 - PublicationOpen AccessApplication of acoustic techniques in the evaluation of heterogeneous building materials(2009-10-23)
; ; ;Fais, S.; DIGITA - Dipartimento di GeoIngegneria e Tecnologie Ambientali - Università di Cagliari ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; In this paper, we present the results of an application of in situ non-destructive acoustic techniques to analyse the state of preservation of a colonnade of an ancient church in the Central Sardinia (Italy). In particular, low frequency ultrasonic tests and seismic longitudinal wave transmission tomography (SLWTT) techniques were applied on the columns of the church in order to provide information on their state of preservation and to detect possible defects, such as zones of weakness, damages and cracks in its inner parts that cannot be visually examined. In order to improve the velocity input model for the SLWTT, a new experimental procedure based on the calculation of the cross-correlation function was proposed and usefully applied. An estimate of the accuracy of the longitudinal wave velocity measurements by SLWTT methods was carried out by application of a standard error analysis based on the law of propagation of uncertainty. Based on the results obtained with the ultrasonic and seismic investigations, we located microcores that confirmed information from the above non invasive investigations.203 125 - PublicationRestrictedVertical and horizontal crustal movements in central and northern Italy(2011-12)
; ; ; ; ; ; ;Baldi, P.; Dipartimento di Fisica, Università di Bologna, Italy ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Cenni, N.; Dipartimento di Fisica, Università di Bologna, Italy ;Loddo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Pesci, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Bacchetti, M.; Dipartimento di Fisica, Università di Bologna, Italy; ; ; ; ; The data from continuous GPS stations located in central and northern Italy, installed with different criteria and planned for scientific or commercial aims, are analyzed to provide the actual crustal movements. The mean velocity of 185 sites have been used to describe both the horizontal and vertical displacement field: the results indicate that the outer part of the Apennine belt moves in a north-eastern direction significantly faster than the inner Tyrrhenian side of the same chain; both Alpine and Apenninic regions show a low uplift, while in the central and eastern sector of the Po Plain the subsidence rate is constant or, in some cases, is decreasing with respect to the values obtained from the last measurements, performed up to 2006 by means of both SAR and leveling techniques. Only the central part of the eastern Po Plain close to the Apennine border (Modena city area) seems to be characterized by an anomalous rate subsidence (15 mm/yr).607 24 - PublicationRestrictedMonitoraggio e controllo dei beni monumentali: formazione e certificazione del personale(2013-12)
; ; ; ; ; ; ; ; ; ; ;Musacchio, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Buongiorno, M. F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Bianchi, M. G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Bonali, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Caserta, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Govoni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Gaudiosi, I.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Porco, G.; SISMLAB s.r.l., Via P. Pietro Bucci, Università della Calabria - 87036 Rende (CS) ;Romano, D.; SISMLAB s.r.l., Via P. Pietro Bucci, Università della Calabria - 87036 Rende (CS); ; ; ; ; ; ; ; ; ; Il presente lavoro costituisce una proposta per la formazione e la certificazione del personale che opera nel campo dei controlli e del monitoraggio dei beni monumentali ubicati in area sismica. Per bene Monumentale si intende qualsiasi manufatto con connotati a valenza storico-artistica, realizzato prevalentemente in muratura, con eventuali elementi in calcestruzzo armato e/o legno. L'articolo scaturisce da una proposta di formazione da sviluppare nell'ambito del Progetto PON denominato MASSIMO, acronimo di "Monitoraggio in Area Sismica Sistemi Monumentali" e dal quale estrarre mirati percorsi di addestramento da inserire in un preciso contesto di certificazione, secondo gli usuali livelli di conoscenza previsti dalla norma UNI EN ISO 9712 "Prove non distruttive - Qualificazione e certificazione del personale addetto alle prove non distruttive". Il contributo espone il percorso formativo relativo al progetto di ricerca e illustra le peculiarità e gli obbiettivi di alcune attività di controllo e monitoraggio basate su tecniche NDT. Per le tecniche maggiormente utilizzate nel processo di controllo, sono elencate le conoscenze minime richieste e le ore di attività necessarie, a giudizio di chi scrive, per poter giungere ad una conoscenza più o meno approfondita del metodo, in base ai diversi livelli di competenza ed al fine di sostenere gli esami di certificazione.1093 62 - PublicationOpen AccessAn experimental application of a 3D terrestrial laser scanner and acoustic techniques in assessing the quality of the stones used in monumental structures(2009-09)
; ; ; ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Fais, S.; DIGITA - Dipartimento di GeoIngegneria e Tecnologie Ambientali - Università di Cagliari - Italy ;Ligas, P.; DIGITA - Dipartimento di GeoIngegneria e Tecnologie Ambientali - Università di Cagliari - Italy; ; Abstract This paper briefly describes the preliminary results of an experimentation aimed to test a new non-destructive methodology based on the integrated application of 3-D terrestrial laser scanning and acoustic techniques in the ultrasonic range (54 kHz) in evaluating the quality of carbonatic stone materials. Our target is to evaluate the state of conservation of stone building materials by correlating ultrasonic longitudinal pulse velocity and frequency spectra of the ultrasonic signals with the reflectivity or reflectance of the reflected 3-D laser scanner beam pulse transmitted to the target of an investigated surface.219 33 - PublicationOpen AccessComparison of the historic seismicity and strain-rate pattern from a dense GPS-GNSS network solution in the Italian PeninsulaWe present a dense crustal velocity field and corresponding strain-rate pattern computed using Global Positioning System (GPS)- Global Navigation Satellite System (GNSS) data from several hundred permanent stations in the Italian Peninsula. GPS data analysis is based on the GAMIT/GLOBK 10.6 software, which was developed and maintained mainly by Massachusetts Institute of Technology (MIT), using tools based on the distributed-sessions approach implemented in this package. The GPS data span the period from January 2008 to December 2012 and come from several different permanent GPS networks in Italy. The GLOBK package implemented in the last version of the GAMIT package is used to compute the position time-series and velocities registered in the International Terrestrial Reference Frame (ITRF) 2008. The resulting high-density intra-plate velocity field provides indications of the tectonics of the Mediterranean region. A computation of the strain-rate pattern from GPS data is performed and compared with the map of the epicentral locations of historical earthquakes that occurred in the last 1000 years in the Italian territory, showing that, in general, higher crustal deformation rates are active in regions affected by seismicity of greater magnitude.
1015 165 - PublicationOpen AccessHigh resolution 3-D modelling of cylinder shape bodies applied to ancient columns of a church(2020-10-28)
; ; ; ; ; ; ; ; ; The use of Non-Destructive Testing (NDT) applied to construction materials allows to highlight and characterize their features, especially in the case of old buildings. The multi-technique high resolution 3D modelling described here is aimed to investigate the conservation state of the central column of a colonnade in the ancient church of Saints Lorenzo and Pancratio, dating to about the second half of the thirteenth century and located in the old town of Cagliari (Italy). This column was considered of interest because its longitudinal axis deviates from its ideal position and it appears the most deteriorated. In this work we describe the integrated application of 3D diagnostic methods, i.e. Terrestrial Laser Scanner (TLS), close range photogrammetry (CRP) and ultrasonic tomography supported by petrographic investigations. They were used to improve the diagnostic process of the conservation state of the investigated column. The TLS technique was supported by CRP to obtain a natural colour texturized 3D model of the column. The geometrical anomaly maps derived from the data of the TLS-CRP survey show the presence of some anomalies worthy of attention. Starting from the 3D reconstruction with previous techniques we planned and implemented a 3D ultrasonic tomography. Ultrasonic tomography proved to be a successful tool in identifying internal defects, as well as the presence of voids and flaws within the materials through the analysis of the propagation of ultrasonic waves. The integration of the three non-invasive techniques supported by petrographical analyses demonstrates its potential in reducing ambiguities since each technique brings its clue to the overall diagnostic process.756 14