Stability analysis of lateritic waste deposits   总被引：1，自引：0，他引：1  

Kamel Omraci  Vronique Merrien-Soukatchoff  Jean-Paul Tisot  Jack-Pierre PiguetLe Nickel-SLN 《Engineering Geology》2003,68(3-4):189-199

In open-pit mines covered with lateritic soil, the sterile ground is stored in specially prepared sites. The waste area must then be enhanced in order to extend storage capacity.

To better understand the effect of an elevated dump, typical laboratory tests (triaxial and oedometer tests) have been performed on the lateritic material. The waste disposal site has been modeled using both limit equilibrium and finite element methods. Different types of finite element models have been run; they take the variation of Young's modulus with depth into account and simulate the effect of construction over various phases. Modeling results are then compared with in situ measurements.  相似文献   

Laboratory simulation of an oxidizing perturbation in a deep granite environment     

Laurent TrotignonValrie Michaud  Jean-Eric Lartigue  Jean-Paul AmbrosiLaurent Eisenlohr  Lise GriffaultMichel de Combarieu  Sylvie Daumas 《Geochimica et cosmochimica acta》2002,66(14):2583-2601

An experiment designed to study oxidizing perturbations in deep crystalline rock, a potential host for nuclear waste disposal, was conducted. This experiment simulated a fracture surface in contact with circulating groundwater, in which dissolved oxygen was injected periodically. Major physicochemical and biological parameters were monitored during this 1-yr experiment. Modeling of the results indicates that the kinetics of oxygen uptake may be represented by a simple steady-state rate law combining enzymatic catalysis (Monod) and a first-order rate law. Combined chemical and biological data demonstrate the coupling of organic/inorganic processes during the uptake of dissolved oxygen and the progressive return to reducing conditions. Timescales for these stages are discussed. Experimental results also suggest that iron-reducing bacteria, which are robust and well-adapted microorganisms, play a key role in these interfacial processes. These results show that an operational definition of the “redox buffering capacity” in a granitic medium cannot ignore the effect of bacteria and therefore the controls on bacterial substrates (organic carbon, H₂, CH₄, CO₂).  相似文献   

Multi-technique monitoring of ocean tide loading in northern France     

Muriel Llubes  Nicolas Florsch  Jean-Paul Boy  Martine Amalvict  Pascal Bonnefond  Marie-Noëlle Bouin  Stphane Durand  Marie-France Esnoult  Pierre Exertier  Jacques Hinderer  Marie-Franoise Lalancette  Frdric Masson  Laurent Morel  Joëlle Nicolas  Mathilde Vergnolle  Guy Wppelmann 《Comptes Rendus Geoscience》2008,340(6):379-389

We have organised afield study of ocean tide loading in the northwestern part of France, where tidal amplitudes are known to be among the highest in the world. GPS and gravimetric techniques have already proved their capability to measure such weak and high-frequency signals. In this study, these classical observations are complemented with less usual techniques, such as tiltmeter and Satellite Laser Ranging (SLR) measurements. We present here the preliminary results for a common period of observations spanning from 12–19 May 2004. Additional measurements from the French Transportable Laser Ranging Station (FTLRS) were available during September and October 2004. Observation residuals are computed as the difference between the observed and the predicted time signals. We obtain small RMS residuals for GPS measurements (2.5/3.1/4.5 mm for the eastward, northward and upward components), for absolute and relative gravimetry (9 nm/s² and 13 nm/s²) and for tiltmeters (0.05 μrad for EW component). We also fit the amplitude of the main M2 tidal constituent to FTLRS observations and we find a value of 3.731 cm, which is comparable to the theoretical value.  相似文献   

Modern methods in Structural Geology and Tectonics: a series of articles in honour of Martin Burkhard (1957-2006)     

Stefan M. Schmid  Neil Mancktelow  Jon Mosar  O. Adrian Pfiffner  Jean-Paul Schaer 《Swiss Journal of Geoscience》2008,101(2):245-249

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War landform mapping and classification on the Verdun battlefield (France) using airborne LiDAR and multivariate analysis     

Rémi de Matos-Machado  Jean-Pierre Toumazet  Jean-Claude Bergès  Jean-Paul Amat  Gilles Arnaud-Fassetta  François Bétard  Clélia Bilodeau  Joseph P. Hupy  Stéphanie Jacquemot 《地球表面变化过程与地形》2019,44(7):1430-1448

Acting as efficient earth-movers, soldiers can be viewed as significant geomorphological drivers of landscape change when replaced in the recent debates on Anthropocene Geomorphology. ‘Polemoforms’, generated by military activities, correspond with a set of human-made landforms of various sizes and geometries. They are particularly common on the World War One battlefield of Verdun (France) which ranks among the largest battles of attrition along the Western Front. The artillery bombardments and building of defensive positions in that battle significantly altered the landscape, resulting in thousands of shell craters, dugouts, and gun positions that have altered both the meso and microtopography. This paper proposes an innovative methodology to make an exhaustive inventory of these small-scale conflict-induced landforms (excluding linear features such as trenches) using a digital terrain model (DTM) acquired by airborne LiDAR on the whole battlefield. Morphometric analysis was conducted using Kohonen's self-organizing maps (SOMs) and hierarchical agglomerative clustering (HAC) in order to quantify and classify the high number of war landforms. This combined approach allowed for mapping more than one million landforms which can be classified into eight different shapes including shell craters and various soldier-made landforms (i.e. shelters, gun positions, etc.). Detection quality evaluation using field observations revealed the algorithm successfully classified 93% of shell craters and 74% of anthropologically constructed landforms. Finally, the iconographic database and map series produced will help archaeologists and foresters to better manage the historic site of Verdun, today covered by a large forest of ~10 000 ha. © 2019 John Wiley & Sons, Ltd.  相似文献   

Changes in seabed morphology, mud temperature and free gas venting at the Håkon Mosby mud volcano, offshore northern Norway, over the time period 2003–2006     

Jean-Paul Foucher  Stéphanie Dupré  Carla Scalabrin  Tomas Feseker  François Harmegnies  Hervé Nouzé 《Geo-Marine Letters》2010,30(3-4):157-167

The Håkon Mosby mud volcano is a 1.5-km-diameter geological structure located on the Southwest Barents Sea slope at a water depth of 1,270 m. High-definition seabed mapping of the mud volcano has been carried out in 2003 and 2006. A comparative analysis of the bathymetry and backscatter maps produced from the two surveys shows subtle morphological changes over the entire crater of the mud volcano, interpreted to be the consequence of mud eruption events. Mud temperature measurements point to a persistently warm mud at shallow depth in the crater. This is explained by upward fluid advection, rather than conductive cooling of mud flows. The small-scale spatial variability in the temperature distribution may be related to mud outflows or changes in the fluid flow regime. Furthermore, the locations of free gas venting observed in 2006 were found to differ from those of 2003. Our observations of overall similar topographic profiles across the mud volcano in 2003 and 2006 suggest that eruption events would have been modest. Nevertheless, the data bring evidence of significant change in activity even over short time intervals of only 3 years. This may be a characteristic shared by other submarine mud volcanoes, notably those considered to be in a quiescent stage.  相似文献   

Cold seep communities in the deep eastern Mediterranean Sea: composition, symbiosis and spatial distribution on mud volcanoes   总被引：2，自引：0，他引：2  

Karine Olu-Le Roy  Myriam Sibuet  Aline Fiala-Mdioni  Serge Gofas  Carmen Salas  Andr Mariotti  Jean-Paul Foucher  John Woodside 《Deep Sea Research Part I: Oceanographic Research Papers》2004,51(12):1915-1936

Two mud volcano fields were explored during the French–Dutch MEDINAUT cruise (1998) with the submersible NAUTILE, one south of Crete along the Mediteranean Ridge at about 2000 m depth (Olimpi mud field) and the other south of Turkey between 1700 and 2000 m depth (Anaximander mud field) where high methane concentrations were measured. Chemosynthetic communities were observed and sampled on six mud volcanoes and along a fault scarp. The communities were dominated by bivalves of particularly small size, belonging to families commonly found at seeps (Mytilidae, Vesicomyidae, Thyasiridae) and to Lucinidae mostly encountered in littoral sulfide-rich sediments and at the shallowest seeps. Siboglinid polychaetes including a large vestimentiferan Lamellibrachia sp. were also associated. At least four bivalve species and one siboglinid are associated with symbiotic chemoautotrophic bacteria, as evidenced by Transmission Electronic Microscopy and isotopic ratio measurements. Among the bivalves, a mytilid harbors both methanotrophic and sulfide-oxidizing bacteria. Video spatial analysis of the community distribution on three volcanoes shows that dense bivalve shell accumulations (mainly lucinids) spread over large areas, from 10% to 38% of the explored areas (2500–15000 m²) on the different volcanoes. Lamellibrachia sp. had different spatial distribution and variable density in the two mud volcano fields, apparently related with higher methane fluxes in the Anaximander volcanoes and maybe with the instability due to brines in the Olimpi area. The abundance and richness of the observed chemosynthetic fauna and the size of some of the species contrast with the poverty of the deep eastern Mediterranean. The presence of a specialized fauna, with some mollusk genera and species shared with other reduced environments of the Mediterranean, but not dominated by the large bivalves usually found at seeps, is discussed.  相似文献   

Comment on ‘Magnetic studies of magma-supply and sea-floor metamorphism: Troodos ophiolite dikes’, by G.J. Borradaile and D. Gauthier     

Jean-Paul Callot  Laurent Geoffroy  Charles Aubourg 《Tectonophysics》2007,433(1-4):141-147

Anisotropy of magnetic susceptibility is used as a proxy for the determination of magmatic flow direction in mafic dykes. Here we take advantage of the dataset from G.J. Borradaile and D. Gauthier to comment three points: (1) the sampling strategy; (2) the geometric relationship between magnetic axis dyke, and, (3) an alternative interpretation to obtain a flow direction. The magnetic lineations published by Borradaile and Gauthier correspond to the zone axis of the dyke and magnetic foliation poles, questioning the reliability of the magnetic lineation as a flow estimate. An alternative interpretation is based on the use of the tiling of the magnetic foliation plane against the dyke wall.  相似文献   

Analysis of karst hydrodynamics through comparison of dissolved and suspended solids' transport     

Danièle Valdes  Jean-Paul Dupont  Nicolas Massei  Benoît Laignel  Joël Rodet 《Comptes Rendus Geoscience》2005,337(15):1365-1374

In karst systems, rain events often result in a decrease of the conductivity (a tracer of dissolved phase transport) and an increase in turbidity (a tracer of suspended solids transport) at wells and springs. This study shows that the comparison of suspended solids and solute transport by the coupled approach of $T\text{–}C$ curves (Turbidity–Conductivity) and autocorrelations gives evidence of the transport processes in the karst network and allows understanding the karst hydrodynamics. To cite this article: D. Valdes et al., C. R. Geoscience 337 (2005).  相似文献   

A multiply imaged, submillimetre-selected ultraluminous infrared galaxy in a galaxy group at z∼ 2.5     

Jean-Paul Kneib  Paul P. van der Werf  Kirsten Kraiberg Knudsen  Ian Smail  rew Blain  Dave Frayer  Vicki Barnard  Rob Ivison 《Monthly notices of the Royal Astronomical Society》2004,349(4):1211-1217

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