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

Open-addressing hashing with unequal-probability keys

This paper describes the use of a drone in collecting data for mapping discontinuities within a marble quarry. A topographic survey was carried out in order to guarantee high spatial accuracy in the exterior orientation of images. Photos were taken close to the slopes and at different angles, depending on the orientation of the quarry walls. This approach was used to overcome the problem of shadow areas and to obtain detailed information on any feature desired. Dense three-dimensional (3D) point clouds obtained through image processing were used to rebuild the quarry geometry. Discontinuities were then mapped deterministically in detail. Joint attitude interpretation was not always possible due to the regular shape of the cut walls; for every discontinuity set we therefore also mapped the uncertainty. This, together with additional fracture characteristics, was used to build 3D discrete fracture network models. Preliminary results reveal the advantage of modern photogrammetric systems in producing detailed orthophotos; the latter allow accurate mapping in areas difficult to access (one of the main limitations of traditional techniques). The results highlight the benefits of integrating photogrammetric data with those collected through classical methods: the resulting knowledge of the site is crucially important in instability analyses involving numerical modelling.Part of 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). The authors acknowledge M. Pellegri and D. Gullì (USL1, Mining Engineering Operative Unit – Department of Prevention), M. Ferrari, M. Profeti and V. Carnicelli (Cooperativa Cavatori Lorano), X. Chaoshui and P.A. Dowd (School of Civil, Environmental and Mining Engineering, University of Adelaide, South Australia) and M. Bocci (Geographike) for their support of this research

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)

Investigations using Csiro Hi triaxal cells for measuring the stress state of rock masses subject to mining extraction: numerical modelling of in-situ extracted core samples

The measurement of the stress state of rock, carried out in-situ using the overcoring CSIro hI Cell technique, provides valuable information about the rock mass geo-structural and stress conditions. this is particularly useful for calibrating the numerical model of natural slopes and excavations fronts and for assessing their static conditions. thus, it allows to improve workplace safety conditions in both open-pit and underground quarries. During an in-situ CSIro test, the stress release strains are measured by 12 strain gauges differently oriented in the space and the stress tensor and the material elastic parameters are then computed. the classic interpretative procedure of stress release test refers to analytical formulations that assume an extracted sample of regular cylindrical shape. however, during overcoring, it may happen that a discontinuity is intercepted, causing the extracted core to break and to assume an irregular shape. to address this challenge, in this work, a Finite Element numerical simulation of stress release was conducted basing on a 3D digital model of the irregular sample resulting from a Photogrammetric Survey. this allowed for the computation of the stress tensor for both irregularly shaped and ideal cylindrical samples. the research proceeded as it follows: i) three-dimensional modelling of the irregularly shaped core using Photogrammetric techniques and mesh Editing, which enabled the accurate representation of complex geometries; ii) numerical modelling of the irregularly shaped core containing the CSIro hI Cell through Finite Element Analysis, providing insights about stress and deformation distributions; iii) stress State of the rock calculation using a multiple Linear regression Procedure by using the coefficient matrix as determined by the core numerical modelling. the implementation of this procedure may facilitate the determination of stress state for irregularly shaped cores, and it enhances to understand how shape and rock elastic properties may influence the stress release behaviour. this comprehensive approach could allow to address challenges associated to stress assessment for irregular shaped rock cores and to improve the accuracy and applicability of geotechnical engineering methods

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

Stress–Strain Investigation of the Rock Mass Based on Overcoring with CSIRO HI Cell Test and Numerical Modeling: A Case Study from an Italian Underground Marble Quarry

The present research illustrates the application of a methodological approach to studying the stress–strain distribution in a marble quarry of the Apuan Alps mining area (Italy). This study has been carried out in the framework of a project involving the University of Siena and the UOC Ingegneria Mineraria—USL Toscana Nord-Ovest, Tuscany Region. This stress–strain analysis aims foremost to monitor the slope stability conditions to guarantee a safe workplace for the personnel involved in mining activities, and to enable more sustainable long-term planning for excavation and production. The involved survey activities are as follows: (i) terrestrial laser scanning; (ii) engineering–geological data mapping; and (iii) in situ marble stress measuring through four CSIRO-type cell tests executed in different locations and at various depths within the underground excavation walls. The gathered data converged into numerical models of the quarry, both in 2D (DEM) and 3D (FEM), calibrated by in situ stress results through a rigorous back analysis assessment using least squares procedures. The created models represent a valuable tool for the identification and securing of risk areas and for future excavation planning in respect of the site efficiency and safety

EFEITOS DA VINHOTERAPIA EM PARÂMETROS SANGUÍNEOS. (COLESTEROL, GLICOSE E TRIGLICERÍDEOS)

É expressivo o número de evidências acerca das propriedades benéficas do vinho para a saúde humana. Estudos recentes comprovaram que certas substâncias presentes no vinho, os compostos fenólicos, possuem atividade antioxidante inibindo a oxidação do LDL - Colesterol. Além da ação antioxidante, mecanismos antiplaquetários, antiinflamatórios e vasodilatadores. Segundo estudos, o etanol eleva os níveis sangüíneos de HDL - Colesterol também faz parte das propriedades do vinho. Entretanto, por ser uma bebida alcoólica, é importante ressaltar que o vinho deve ser consumido com moderação, sendo que o consumo excessivo passa a ser fator de diversas doenças. O presente estudo analisou trinta pacientes com alimentação normal, ingerindo vinho tinto Cabernet Sauvignon, Isabel e Chardonnay durante a refeição principal, num período de trinta dias, acompanhado por exames sanguíneos: colesterol total, HDL- Colesterol, LDL- Colesterol, triglicerídeos e glicemia pré-vinho e pós-vinho. Com relação aos exames laboratoriais estes apresentaram um aumento significativo no HDL - Colesterol (p<0,05) apenas com o grupo que teve a ingestão do vinho Isabel