1,721,125 research outputs found
Geomatics for slope stability and rock fall runout analysis: A case study along the Alta Tambura road in the Apuan Alps (Tuscany, Italy)
No full textWith increasing awareness of geological risks, the study of rocky slopes plays a key role in the Earth Sciences, especially in areas of high vulnerability due to the presence of human settlement. The present paper describes the stability and runout analyses carried out along the Alta Tambura road, in correspondence with the Guadine village connecting the Massa urban settlement to the Apuan Alps (Tuscany, Italy). The integration among various types of survey and analytical methodologies allowed for the application of up-to-date approaches for hazard assessment. Results from these types of studies are useful in the decision-making process concerning choosing the most appropriate mitigation works and, as in such a case, their a posteriori validation. With regard to the survey techniques, terrestrial laser scanning and digital close-range photogrammetry were used to produce the digital elevation model, oriented stereo-images, orthophotos and accurate positions and volumes of rocky wedges and joints located on the slope overhanging the analyzed road. Thanks to this data, a deterministic stability analysis was conducted and the spatial distribution of rock fall density, velocities and kinetic energies was modeled by means of the "cone-method". Historical evidence of rock falls, identified during fieldwork activities and photointerpretation, were used to assess and calibrate the accuracy of results obtained from the method and allowed, through a further 2D rock fall runout analysis, the calculation of the dissipation energy that protection measures need to mitigate the risk in the area
Laser Scanning for the definition of high resolution topography in the Apuan Alps (IT) marble district
No full textAnalisi spaziale della distribuzione della ceramica nel complesso dell’area A
No full textLa quanti,cazione dei pezzi ceramici scavati è risultata utile per la successiva fase di analisi e confronto delle varie classi e forme recuperate all’interno dei singoli vani. Questo approccio quantitativo è nato dalla volontà di dislocare e descrivere, all’interno dell’edi,cio, la distribuzione dei pezzi ceramici appartenenti alle varie classi e forme e delle quantità complessive pesate di ciascuna classe. A questo scopo, si è deciso di procedere alla gestione dei dati quantitativi di scavo attraverso un’applicazione GIS (Geographic Information System) che permettesse di eseguire correlazioni spaziali tra la componente geogra,ca, costituita dalla pianta di scavo, e una consistente componente alfanumerica, rappresentata dalla totalità dei dati quantitativi relativi ai pezzi ceramici scavati. L’impiego della tecnologia GIS ha permesso di elaborare una serie di mappe tematiche di distribuzione con la funzione di mostrare, in maniera chiara, la distribuzione delle quantità dei pezzi scavati, classi,cati in base all’appartenenza ad una determinata classe ceramica o forma ceramica e in base allo loro quantità pesata
UAV and DGPS surveys as support to mining activities: the case of Sa Pigada Bianca area (Ittiri, Italy)
No full textScopo del presente lavoro è stato quello di creare la nuova topografia di dettaglio della concessione mineraria sita nell’area di Sa Pigada Bianca (Comune di Ittiri, Sassari – Italia). La necessità di conoscere in maniera accurata, quindi mediante una cartografia di grande scala, la morfologia delle aree di estrazione e di ripristino ha spinto gli Autori a preferire la realizzazione di un volo fotogrammetrico da UAV (Unmanned Aerial Vehicle o drone) rispetto ad una presa aerea tradizionale o ad un rilievo topografico classico. Per poter riferire la nuova carta topografica prodotta a quella ufficiale della Regione Sardegna è stato eseguito un rilievo GPS in modalità differenziale di appoggio al lavoro fotogrammetrico effettuato col drone, verificandone preventivamente la conformità con i punti trigonometrici ufficiali.
A partire dall’interpretazione dei dati stereoscopici, delle nuvole di punti tridimensionali georiferite e delle ortofoto prodotte è stata creata, mediante stereorestituzione digitale, una nuova cartografia dell'area di studio alla scala 1:1.000 con indicati i gradoni, i cigli, le scarpate, i fronti e tutti gli elementi distintivi delle coltivazioni e delle pareti residue. La planimetria contiene inoltre anche gli elementi caratteristici della rete idrografica, i punti quotati, le isoipse con equidistanza pari a 1 metro ed i toponimi
Il rilievo geostrutturale dei fronti rocciosi: confronto tra accuratezze di dati provenienti da Fotogrammetria Digitale Terrestre e Laser Scanning
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Modellazione stocastica della fratturazione (Metodo Discrete Fracture Network) a supporto della stima previsionale di resa all’interno di bacini estrattivi di pietre ornamentali
No full textThe present paper shows a working approach aimed at improving quarry yield prediction accuracy in ornamental stone basins. In such contest, the yield prediction is subjected toa degree of uncertainty due to several factors, as the fracture network, the geomechanical properties of the rock and other qualitative characteristics of the ornamental stones. To decrease such uncertainty, we proposed an approach based on the Discrete Fracture Network (DFN) technique. The DFN is a stochastic approach for reproducing the discontinuity pattern starting from deterministic measurements of different parameters acquired during field surveys, as for example fracture intensity and density. A specific algorithm creates a fracture network compatible from a statistic point of view with the data collected on the quarry rock faces, overcoming the limitations of a purely deterministic approach. This study used the DFN methodology in a marble quarry (Apuan Alps, Italy), where it has been possible to increase the reliability of the quarry yield prediction in terms of dimension of extractable intact blocks, which is the starting point of a series of other qualitative considerations
Did the Nile River flow to the Gulf of Sirt during the late Miocene?
No full textSatellite imageries from Landsat ETM+ and ERS (European Remote Sensing) Radar sensors, together with elevation data collected by the Shuttle Radar Topography Mission (SRTM) in addition to recent and older bibliography, have led to the hypothesis that, before the Late Messinian drawdown of the Mediterranean Sea, the River Nile flowed into the Libyan palaeo-Sirt. The study is still in progress; in this paper data are presented from three areas, showing evidence of palaeo-drainage of Tortonian-Late Messinian age, that could be considered sufficient to delineate the course of the Nile River up to the Gulf of Sirt (fig. 1)
Monitoring of strain and temperature in an open pit using brillouin distributed optical fiber sensors
Full text linkMarble quarries are quite dangerous environments in which rock falls may occur. As many workers operate in these sites, it is necessary to deal with the matter of safety at work, checking and monitoring the stability conditions of the rock mass. In this paper, some results of an innovative analysis method are shown. It is based on the combination of Distributed Optical Fiber Sensors (DOFS), digital photogrammetry through Unmanned Aerial Vehicle (UAV), topographic, and geotechnical monitoring systems. Although DOFS are currently widely used for studying infrastructures, buildings and landslides, their use in rock marble quarries represents an element of peculiarity. The complex morphologies and the intense temperature range that characterize this environment make this application original. The selected test site is the Lorano open pit which is located in the Apuan Alps (Italy); here, a monitoring system consisting of extensometers, crackmeters, clinometers and a Robotic Total Station has been operating since 2012. From DOFS measurements, strain and temperature values were obtained and validated with displacement data from topographic and geotechnical instruments. These results may provide useful fundamental indications about the rock mass stability for the safety at work and the long-term planning of mining activities
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