A case study integrating remote sensing and distinct element analysis to quarry slope stability assessment in the Monte Altissimo area, Italy

This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.enggeo.2014.09.003. First available online 22 September 2014Over last decade geomatic techniques have been increasingly used for the geometrical characterization of rock slopes. Terrestrial laser scanning and digital terrestrial photogrammetry in particular are now frequently used in the characterization of joint surfaces and slope geometry. Although the use of these techniques for the structural characterization of slopes is widely documented, limited research has been undertaken to improve our understanding of the importance of the derived data quality in the construction of slope geometry imported into 3D numerical models. One of the most common problems encountered in the use of these techniques, especially in case of slopes with complex geometry, is the presence of occlusions. In this context, the aims of this paper are to describe how the integrated use of terrestrial laser scanning, digital terrestrial photogrammetry and topographic surveys can mitigate the influence of occlusions and how the slope geometry gained from these surveys can be important in slope stability analyses. For this purpose a case study in the Monte Altissimo area (Apuan Alps, Italy) will be presented. Several geomatic techniques were used for studying a slope overhanging the Granolesa quarry. Special emphasis will be given to the importance of using Total Station and Differential GPS surveys as tools for data fusion. Moreover, in order to validate this procedure, the accuracy and precision of the output were determined through comparison of 3D models derived from laser scanning and digital terrestrial photogrammetry.Furthermore, two different analyses with the three-dimensional distinct element code, 3DEC, were carried out in order to highlight the advantages and limitations of using data obtained from terrestrial remote sensing techniques as opposed to models based on topographic maps.The authors wish to thank the Tuscany Region which funded this research (Announcement 6744/2008 POR CREO 2007–2013). Moreover, we are extremely grateful to Henraux S.p.A., Prof. Pier Lorenzo Fantozzi (University of Siena), Geol. Sergio Mancini, Geol. Vinicio Lorenzoni and Ing. Matteo Lapini (Ingeo Systems s.r.l.) for their assistance and advices in this research

A GPU-based survey for millisecond radio transients using ARTEMIS

Astrophysical radio transients are excellent probes of extreme physical processes originating from compact sources within our Galaxy and beyond. Radio frequency signals emitted from these objects provide a means to study the intervening medium through which they travel. Next generation radio telescopes are designed to explore the vast unexplored parameter space of high time resolution astronomy, but require High Performance Computing (HPC) solutions to process the enormous volumes of data that are produced by these telescopes. We have developed a combined software /hardware solution (code named ARTEMIS) for real-time searches for millisecond radio transients, which uses GPU technology to remove interstellar dispersion and detect millisecond radio bursts from astronomical sources in real-time. Here we present an introduction to ARTEMIS. We give a brief overview of the software pipeline, then focus specifically on the intricacies of performing incoherent de-dispersion. We present results from two brute-force algorithms. The first is a GPU based algorithm, designed to exploit the L1 cache of the NVIDIA Fermi GPU. Our second algorithm is CPU based and exploits the new AVX units in Intel Sandy Bridge CPUs.Comment: 4 pages, 7 figures. To appear in the proceedings of ADASS XXI, ed. P.Ballester and D.Egret, ASP Conf. Se

Geological 3D modeling for excavation activity in an underground marble quarry in the Apuan Alps (Italy)

The three-dimensional laser scanning technique has recently become common in diverse working environments. Even in geology, where further development is needed, this technique is increasingly useful in tackling various problems such as stability investigations or geological and geotechnical monitoring. Three-dimensional laser scanning supplies detailed and complete geometrical information in short working times, as a result of the acquisition of a large number of data-points that accurately model the detected surfaces. Moreover, it is possible to combine these data with high quality photographic images so as to provide important information for geological applications, as follows. A working approach, that combines terrestrial laser scanning and traditional geological surveys, is presented. A three-dimensional model, that includes information about the geological structure in an underground quarry in the Apuan Alps, is realized. This procedure is adaptable to other geological contexts, and because of its operating speed and accuracy it is invaluable for optimal excavation, in which a proper planning of quarrying activity is vital for safety and commercial reasons. © 2014 Elsevier Ltd.The authors gratefully acknowledge the assistance of the personnel of the Romana Quarry and particularly Geol. Massimo Corniani. This paper was possible because of support from the Tuscany Region Research Project known as “Health and safety in the quarries of ornamental stones – SECURCAVE”

Application of an integrated geotechnical and topographic monitoring system in the Lorano marble quarry (Apuan Alps, Italy)

PublishedThis is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.geomorph.2015.04.009Accurate slope stability analysis is essential for human activity in high-risk geological contexts. This may, however, not be enough in the case of quarrying where the dynamic and evolving environment also requires effective monitoring. A well-designed monitoring system requires the acquisition of a huge dataset over time, improving knowledge of the study area and helping to refine prediction from stability analysis.This paper reports the implementation of an integrated monitoring system in a marble quarry in the Apuan Alps (Italy) and some of the results obtained. The equipment consists of a traditional geotechnical monitoring system (extensometers, crackmeters and clinometers) and two modern topographic monitoring systems (a terrestrial interferometer and a robotic total station). This work aims to provide in-depth knowledge of the large scale rock mass behaviour as a result of marble exploitation, thereby allowing continuous excavation. The results highlight the importance of integrating different monitoring systems.The present study was undertaken within the framework of the Italian National Research Project PRIN2009, funded by the Ministry of Education, Universities and Research, which involves the collaboration between the University of Siena, “La Sapienza” University of Rome, and USL1 of Massa and Carrara (Mining Engineering Operative Unit - Department of Prevention)

An RBF Meshless Approach to Evaluate Strain Due to Large Displacements in Flexible Printed Circuit Boards

Thin plates are very often employed in a context of large displacements and rotations, for example, whenever the extreme flexibility of a body can replace the use of complicated kinematic pairs. This is the case of the flexible Printed Circuit Boards (PCBs) used, for example, within last-generation foldable laptops and consumer electronics products. In these applications, the range of motion is generally known in advance, and a simple strategy of stress assessment leaving out nonlinear numerical calculations appears feasible other than desirable. In this paper, Radial Basis Functions (RBFs) are used to represent a generic transformation of a bi-dimensional plate, with all the derivate fields being analytically achieved without the need for a numerical grid for large-displacement applications. Strains due to bending are easily retrieved with this method and satisfactorily compared to analytical and shell-based Finite Element Method (FEM) benchmarks. On the other hand, the computational costs of the juxtaposed methods appear far different; with the machine being equal, the orders of magnitude of the time elapsed in computation are seconds for the RBF-based strategy versus minutes for the FEM approach

An integrated remote sensing-GIS approach for the analysis of an open pit in the Carrara marble district, Italy: slope stability assessment through kinematic and numerical methods

PublishedJournal Article© 2015 Elsevier Ltd. Over the last decade, terrestrial laser scanning and digital terrestrial photogrammetry techniques have been increasingly used in the geometrical characterization of rock slopes. These techniques provide innovative remote sensing tools which overcome the frequent problem of rock slope inaccessibility. Comprehensive datasets characterizing the structural geological setting and geometry of the slopes can be obtained. The derived information is very useful in rock slope investigations and finds application in a wide variety of geotechnical and mine operations. In this research an integrated remote sensing - GIS approach is proposed for the deterministic kinematic characterization of the Lorano open pit in the Apuan Alps of Italy. Based on the results of geomatic and engineering geological surveys, additional geomechanical analysis using a 3D finite difference method will be presented in order to provide a better understanding of the role of stress-induced damage on slope performance