Дисертації з теми "DEM Soil"
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Fakih, Mahmoud. "Modélisation numérique discrète de la croissance racinaire dans un sol : relation force-forme." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT323/document.
Повний текст джерелаPlant roots play an important role in the growth and development of plants, and it is well known that the mechanical interactions between a growing root and the surrounding soil can have a major impact on root growth and consequently on plant biomass production. These mechanical interactions are one of numerous factors that explain the variability of root architecture, including genetics, environment and developmental instability. But this factor has often been under-estimated. I hypothesize that the heterogeneous structure of soil at the particle scale, demonstrated by the broad distribution of forces, can significantly influence root growth trajectories. This thesis aims at determining how grains in granular soils are reorganized under the action of growing roots, and in return how the resulting forces acting on root tips modify their development, including the kinematics of their trajectories, in order to develop a general biophysical law of root-soil mechanical interactions. I developed a 2D numerical model of root growth in a granular medium using a Discrete Element Model (DEM). The model is able to compute grain-grain and root-grain contact forces within a granular medium. The root system is modelled using chains of connected spheroline elements. The orientation of root growth at every growth step is determined by the dynamics of the whole root under the action of its internal elastic forces and reaction forces exerted by the grains, which are the mechanical interactions that control numerical growth in the model.Parametric studies were carried out in order to (i) estimate the influence of granular structure (grain diameter distribution, cohesion, volume fraction) and root mechanical properties (root bending stiffness) on the axial force signal acting on the root tip, and on the root trajectories and (ii) define general physical laws that can be used further to analyze experimental data. The distribution curves of computed root tip-grain forces normalized by the mean force during a given period of growth were characterized by a decreasing power law for forces below the mean force, and an exponential fall-off for forces above the mean force, thus reflecting the broad distribution of forces inside the granular material. An analysis of the standard deviation of the local deformations of root trajectories resulted in two different regimes with regard root stiffness. In the first regime, soil controlled the root deformation and in the second, the root trajectory was straighter and displaced more significantly the surrounding grains during growth
Yue, Peng. "A micro mechanical study of critical state soil mechanics using DEM." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/38060/.
Повний текст джерелаHuang, Xin, and 黃昕. "Exploring critical-state behaviour using DEM." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206742.
Повний текст джерелаpublished_or_final_version
Civil Engineering
Doctoral
Doctor of Philosophy
Mok, Benjamin Chit Man. "An investigation of strain localization in cemented sands and mechanisms of stiffness anisotropy using the dem simulations /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202007%20MOK.
Повний текст джерелаPreko, Kwasi. "Determination of Volumetric Soil Water Content Using Ground Penetrating Radar Bestimmung des volumetrischen Bodenwassergehaltes mit dem Bodenradar /." [S.l. : s.n.], 2007. http://digbib.ubka.uni-karlsruhe.de/volltexte/1000007396.
Повний текст джерелаNishiyama, Kenta. "Analysis of Soil-Tire Interaction Using a Two-Dimensional Finite Element-Discrete Element Method." Kyoto University, 2019. http://hdl.handle.net/2433/245298.
Повний текст джерелаLi, Jun. "Numerical investigations of the coupled DEM-LBM technique with application to leakage-soil interaction due to a leaking pipe." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4016/.
Повний текст джерелаJakob, Christian. "Numerische Modellierung des Verflüssigungsverhaltens von Kippen des Braunkohlenbergbaus beim und nach dem Wiederaufgang von Grundwasser." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-218045.
Повний текст джерелаBista, Hemanta. "Modeling Hydro-Bio-Chemo-Mechanical Mechanisms in Granular Soils." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1399587419.
Повний текст джерелаPelcat, Yann S. "Soil landscape characterization of crop stubble covered fields using Ikonos high resolution panchromatic images." Thesis, Winnipeg : University of Manitoba, 2006. http://www.collectionscanada.ca/obj/s4/f2/dsk3/MWU/TC-MWU-224.pdf.
Повний текст джерелаA thesis submitted to the Faculty of Graduate Studies in partial fulfillment of the requirements for the degree of Master of Science, Department of Soil Science. Includes bibliographical references.
Link, Adam John. "Identifying Potential Patterns of Wildfires in California in Relation to Soil Moisture using Remote Sensing." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu158646328387007.
Повний текст джерелаBenseghier, Zeyd. "Etude numérique de l'érosion d'un matériau granulaire cohésif par un écoulement fluide." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0579.
Повний текст джерелаHydraulic earthworks are frequently subjected to erosion-induced failure as reported in the literature. Accordingly, several erosion tests have emerged to quantify soil’s erodibility. However, they are based on simplified interpretation models and may lead to some inconsistencies. Despite several experimental investigations on the subject, there is still a lack of understanding of the erosion mechanisms taking place at the grain level. To this end, the LBM-DEM method is used in the present study to analyze numerically the erosion phenomena at the grain scale, with the addition of a cohesion model, including a time-dependent damage law. The computational speed and the efficiency of the code was significantly improved here using GPUs parallelization techniques. Next, after a preliminary analysis of 2D laminar impinging jet flow, the relevance of the classical Shields criterion for cohesion-less samples was first recovered, followed by a proposed generalization of this criterion for weakly cohesive soils with satisfactory agreement. Lastly, an adaptation of the classical JET interpretation model was proposed to our 2D laminar problematic and the erodibility parameters were subsequently quantified and critically discussed. Finally, a constant shear-driven fluid flow configuration at the upper surface of a sample was alternatively studied. A power law function was found to be best suited than the usual linear relation to account for the erosion law at sample scale. A parametric study on inter-particle cohesion and grain size was next performed to investigate the link between micro and macro parameters
Fritz, Heiko. "Berechnung von Schneeschmelze und Wintererosion im Kleineinzugsgebiet „Schäfertal“ mit dem Modell Erosion 3D/Winter Version." Thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2010. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-62395.
Повний текст джерелаCoetzee, C. J. (Cornelis Jacobus). "Forced granular flow." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51764.
Повний текст джерелаENGLISH ABSTRACT: The main goal of the thesis is to validate the ability of discrete element methods (DEM) to predict forced granular flow. Granular flow occurs in a broad spectrum of industrial applications. The thesis focuses on earthmoving processes typical of the mining and agricultural industries. Existing soil mechanics soil-tool models are also investigated and general flow behaviour in and around blades and buckets are established. Soil mechanics theories are used to predict the draft forces on a flat blade moving through granular material. Com and wheat grains are used as material. The rupture (slip) lines in front of the blade are predicted by soil mechanics and compared to experimental results. A two-dimensional test bench is used to visualise the flow of the granular material. Forces and moments that act on the tools are measured. DEM can be used to model industrial granular flow with large displacements. Two types of earthmoving equipment are simulated. The first is a flat blade and the second is a bucket. The forces on these tools are determined using DEM and compared to experimental results. The ability of DEM to predict material compressibility, the flow of material in and around the tools, the rupture lines and the bucket fill rate are investigated. A particle relative displacement method is used to determine the rupture lines.
AFRIKAANSE OPSOMMING: Die hoofdoel van die tesis is om die vermoë van diskrete-element-metodes (DEM) om geforseerde partikelvloei te voorspel, te ondersoek. Partikelvloei word aangetref in 'n breë spektrum van industriële toepassings. Die tesis fokus op grondverskuiwing soos aangetref in myn- en landbouprosesse. Bestaande grondmeganika-modelle word ook ondersoek, asook die algemene gedrag van partikelvloei in en rondom lemme en bakke. Die grondmeganika-modelle word hoofsaaklik gebruik om die kragte op lemme te voorspel. Glip (skuif)-vlakke word ondersoek en vergelyk met eksperimentele resultate. 'n Twee-dimensionele toetsbank word gebruik om die vloei waar te neem. Die kragte en momente op die toerusting word ook gemeet. Mielie- en koringpitte word as materiaal gebruik. DEM kan gebruik word om industriële partikelvloei met groot verplasings te modelleer. Twee tipes toerusting word gesimuleer. Die eerste is 'n plat lem en die tweede 'n bak. Die kragte en momente op dié toerusting word bepaal m.b.V. DEM en dan vergelyk met die eksperimentele resultate. Die vermoë van DEM om materiaalsamedrukking, vloeipatrone, glipvlakke en bakvul-tempo's te voorspel word ondersoek. 'n Partikelrelatiewe- verplasings-metode word gebruik om die glipvlakke te voorspel.
Warren, Georgina. "Developing land management units using Geospatial technologies: An agricultural application." Thesis, Curtin University, 2007. http://hdl.handle.net/20.500.11937/740.
Повний текст джерелаSauvé, Sébastien. "Copper and aluminum free ion activity in soil solutions = L'activité inonique du cuivre et de l'aluminium dans des solutions de sols." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23295.
Повний текст джерелаThe second method is a simple determination of free Cu$ sp{2+}$ in soils using a cupric ion-selective electrode. Free copper has been demonstrated to be the toxicity controlling component in aquatic studies and this study was undertaken to measure free copper activity in soils. The possible interference due to ionic strength variations or the presence of aluminum in the soil solution was checked and found to be negligible. The free activity of copper (pCu$ sp{2+}$) measured in a variety of pristine and contaminated soils varied between 6.33 to 12.20 pCu$ sp{2+}$ units. Total soil copper content and acidity were shown to strongly increase copper solubility and free Cu$ sp{2+}$ activity in the soil solution extracts. (Abstract shortened by UMI.)
Costa, d'Aguiar Sofia. "Numerical modelling of soil-pile axial load transfer mechanisms in granular soils." Châtenay-Malabry, Ecole centrale de Paris, 2008. http://www.theses.fr/2008ECAP1075.
Повний текст джерелаThe purpose of the work presented in this thesis, which has a theoretical and numerical character, is the analysis and numerical modelling of soil-pile load transfer mechanisms, in granular soils, when the pile is subjected to axial vertical loads. In the three dimensional elastoplastic finite element model used, particular attention is paid to modelling soil-structure interface behavior. The necessary numerical tools were implemented and the existing ones enhanced so that, the analysis of the soil-pile interaction problem is feasible. Two newly implemented 3D constitutive laws, in the GEFDYN finite element code, are proposed: an interface model and, for soil, an axisymmetric formulation of the existing ECP multimechanism model, also known as Hujeux model. The performance of both constitutive models is compared with experimental results. First, using soil-structure direct shear tests and then, using results of static pile load tests of centrifuge physical models. The theoretical formulation and numerical implementation of the constitutive models proved to be adequate for the analysis of the soil-pile load transfer mechanisms for different soil initial states, soil-pile surface roughness conditions, and different geometries. Finally, the applicability of the proposed models, is also studied for a real case study of pile static load tests carried out in the ISC'2 experimental site, at the occasion of the 2nd International Conference on the Site Characterization. Soil’s laboratory characterization tests and in-situ pile static load tests on bored and CFA piles are simulated, and results successfully compared
Rull, Patricia. "Hydrological modeling enhancement using GIS : An improved topographic wetness index for wetland detection." Thesis, Stockholms universitet, Institutionen för naturgeografi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-126004.
Повний текст джерелаWarren, Georgina. "Developing land management units using Geospatial technologies: An agricultural application." Curtin University of Technology, Department of Spatial Sciences, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17509.
Повний текст джерелаde, Frias Lopez Ricardo. "Granular Materials for Transport Infrastructures : Mechanical performance of coarse–fine mixtures for unbound layers through DEM analysis." Licentiate thesis, KTH, Jord- och bergmekanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195598.
Повний текст джерелаGrus i form av krossat bergmaterial används i stor utsträckning som obundna bär- och förstärkningslager inom tranportinfrastrukturen och spelar där en viktig roll för verkningsätt, drift och underhåll. Det finns emellertid begränsad kunskap om de fundamentala mekanismerna på partikelnivå (d.v.s. enskilda gruskorn), mekanismer som styr det makromekaniska verkningssättet. Områden såsom väg- och järnvägsbyggnad bygger fortfarande väsentligen på empiriskta baserade modeller p.g.a. dessa materials komplexa uppträdande under belastning. Denna komplexitet beror delvis på den diskreta naturen hos problemet vilket innebär att traditionell matematisk modellering som vore materialen homogena och kontinuerliga, blir inadekvat. Mot denna bakgrund utgör den s.k. diskreta elementmetoden (DEM) ett numeriskt alternativ för att studera verkningssätt hos diskreta system där man explicit beaktar mekanismerna på partikelnivå. Denna avhandling, som baseras på tre vetenskapliga bidrag, syftar till att ge mikromekaniska insikter vad gäller effekten av olika partikelstorlekar på bärförmågan hos grusmateral och dess inverkan på styvhet och motstånd mot permanenta deformationer. Båda dessa parametrar påverkas kraftigt av spänningsnivån och kan studeras genom triaxialförsök. För att undersöka detta studerades med hjälp av DEM binära blandningar av elastiska kulor – den enklaste modellen av grusmaterial med språng i fördelningskurvan – som utsattes för axialsymmetrisk belastning. Denna modell kan i sin tur ses som en förenkling av mer komplexa blandningar. Inledningsvis studerades effekten av finpartikelinnehållet på partikelkontakternas kraftöverföring. Resultaten användes för att klassificera olika typer av skelettstrukturer i grusmaterialet där den finare och den grövre fraktionens roller kvantifierades med utgångspunkt från kraftöverföringen i stället för från det makromekaniska verkningssättet. Resultaten visade en korrelation vad gäller verkningssättet mellan numeriska blandningar och grusmaterial, där de numeriska blandningarna kunde reproducera några av grusmaterials viktigaste kännetecken vad gäller spänningsberoendet för styvheten vid avlastning och motståndet mot permanent deformation. Vidare visades att styvheten kunde bestämmas ur första belastningscykeln vilket underlättar att övervinna de begränsningar avseende beräkningstid som annars förknippas med DEM. God överensstämmelse mellan grusmaterialets skelettstruktur och verkningssätt kunde också observeras. Generellt observerades högre styvhet och mindre permanenta deformationer för interaktiva skelettstrukturer medan det motsatta gällde för instabila strukturer. Numeriska blandningar av elastiska kulor är långt från verkliga grusmaterial, för vilka ett stort antal ytterligare faktorer måste beaktas. Icke desto mindre är det författarens övertygelse att detta arbete ger insikter i grusmaterialets skelettstruktur och dess effekter på det makromekaniska verkningssättet hos grusmaterial.
QC 20161116
Negim, Osama. "New Technique for Soil Reclamation and Conservation: In Situ Stabilization of Trace Elements in Contaminated Soils." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2009. http://tel.archives-ouvertes.fr/tel-00408020.
Повний текст джерелаTaboada, Miguel Angel. "Soil structural behaviour in flooded and agricultural soils of the Argentine pampas." Phd thesis, Toulouse, INPT, 2006. http://oatao.univ-toulouse.fr/7546/1/taboada.pdf.
Повний текст джерелаMunier-Lamy, Colette. "Mobilisation et préconcentration de l'uranium dans les sols : Rôle des substances hymiques." Nancy 1, 1987. http://www.theses.fr/1987NAN10220.
Повний текст джерелаSinak, Sokrat. "Influence comparée de la pédogenèse et des pratiques agricoles sur la fertilité phosphorique des sols." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL108N.
Повний текст джерелаLéger, Emmanuel. "Détermination des propriétés hydrodynamiques des sols par mesures radar de surface." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112189/document.
Повний текст джерелаSoil hydraulic properties, represented by the soil water retention and hydraulic conductivity functions, dictate water flow in the vadose zone, from surface to aquifers. Understanding the water flow dynamic has important implications for estimating available water resources and flood forecasting. It is also crucial in evaluating the dynamicsof chemical pollutants in soil and in assessing the risks of groundwater pollution. Ground Penetrating Radar is a geophysical method particularly suited to measure contrasts of electromagnetic parameters such as those created by water content variations in soils.In this manuscript, we focus on Ground Penetrating Radar temporal monitoring of fluid flows in the near surface, such as infiltration in soil. We were initially curious to know to know if Ground-Penetrating Radar could be used to estimate soil hydraulic properties, more efficiently than classical soil characterization methods such as disk infiltrometer and water hanging column. We developed coupled hydrodynamic and electromagnetic numerical modeling to invert the two way travel times associated with reflections corresponding to strong dielectric permittivity contrasts, such as these involved on infiltration bulbs or fronts orwater tables.We designed two types of Ground Penetrating Radar infiltration monitoring techniques: one using a single ring infiltrometer and the other using shallow boreholes. The first type of infiltration experiment relied on uni-dimensional numerical modeling whereas the second one used a 2D-axi-symmetrical hypothesis. In each of these cases, our original methods have been numerically tested and applied to sandy soils. Beyond quantitative soil hydraulic parameter estimations, electromagnetic wave interactions with hydrodynamicprocesses lead to peculiar phenomena such as waveguide creation by infiltration bulbs.In addition, we showed that Ground Penetrating Radar monitoring was accurate enough to detect the hysteresis of the water retention function during successive drainage and wetting cycles, in a laboratory experiment using a sub-metric tank filled with Fontainebleau sand. The parameters characterizing the hysteresis of this function have been quantified through two-way travel time inversions of the bottom tank reflection during one-step and multi-step hydraulic head experiments
Wadgaonkar, Shrutika. "Nouveaux procédés de bioremédiation pour le traitement des sols et des sédiments sélénifères." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1105.
Повний текст джерелаThe aim of this Ph.D. was to develop a technology for the remediation of seleniferous soils/sediments and to explore microbial reduction of selenium oxyanions under different respiration conditions and bioreactor configurations.Seleniferous soil collected from the wheat-grown agricultural land in Punjab (India) was characterized and its soil washing was optimized by varying parameters such as reaction time, temperature, pH and liquid to solid ratio. In order to maximize selenium removal and recovery from this soil, effect of competing ions and oxidizing agents as chemical extractants for soil washing were also studied. Although oxidizing agents showed a maximum selenium removal efficiency (39%), the presence of oxidizing agents in the leachate and the agricultural soil may increase the cost of their post-treatment. Aquatic plants, Lemma minor and Egeria densa were used to study phytoremediation of the soil leachate containing oxidizing agents. However, the selenium removal efficiency by aquatic weeds was significantly affected by the high concentrations of these oxidizing agents in the soil leachate.Seleniferous soil flushing revealed the selenium migration pattern across the soil column. Migration of soluble selenium fraction from the upper to the lower layers and its subsequent reduction and accumulation in the lower layers of the soil column was observed during soil flushing. The selenium removal efficiency by the soil flushing method decreased with an increase in the column height. Furthermore, the soil leachate containing selenium oxyanions obtained from soil washing was treated in a UASB reactor by varying the organic feed. Effluent containing less than 5 μg L-1 selenium was achieved, which is in accordance with the USEPA guidelines for selenium wastewater discharge limit.Moreover, ex situ bioremediation of selenium oxyanions was studied under variable conditions. An aerobic bacterium (Delftia lacustris) capable of transforming selenate and selenite to elemental selenium, but also to hitherto unknown soluble selenium ester compounds was serendipitously isolated and characterized. Alternatively, anaerobic bioreduction of selenate coupled to methane as electron donor was investigated in serum bottles and a biotrickling filter using marine sediment as inoculum. Finally, the effect of contamination of other chalcogen oxyanions in addition to selenium was studied. Simultaneous reduction of selenite and tellurite by a mixed microbial consortium along with the retention of biogenic Se and Te nanostructures in the EPS was achieved during a 120-day UASB bioreactor operation
Van, Den Bogaert Romain. "Analyse des mécanismes du lessivage des argiles dans les sols par des approches expérimentales." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4315/document.
Повний текст джерелаClay translocation is a widespread process of particle transfer from a surface eluviated horizon to a deeper illuviated horizon. Nevertheless, a number of gaps persist in understanding this process. We therefore investigated: the water flow processes in the active porosity, the effect of rain-interrain cycles on the retention of particles, and the consequences of physical and chemical disturbances of the soil solution on the stability of soil particles in suspension. To address these issues, we have made the choice of a laboratory reductionist approach coupled with modern analytical methods, poorly used in soil science. As a model materials, we used undisturbed luvisol E horizons and natural clay particles extracted from these horizons. We show experimentaly for the first time that macroporous preferential flow consist in rivulets. Our work also provides a first step towards estimating the water-soil specific surface area. We show that particle retention occurs in the matrix close to active macropores, the thickness of the concern matrix being a function of the interrain duration. Finally we have shown that the variations of the calcium concentration and pH of the soil solution, subsequent to the infiltration of rain water into the pores, cause a change in the arrangement of the particles in the soil suspension on a timescale corresponding to the duration of a rainfall event
Bagagli, Yoann. "Modélisation cyclique des sols et interfaces sol/structure." Phd thesis, Ecole Centrale de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00679534.
Повний текст джерелаRoger, Eve. "Mines buried in dry and saturated soils : blast experiments, soil modeling and simulations." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI054/document.
Повний текст джерелаIn recent conflicts, vehicles have been facing underbelly attacks involving a large quantity of buried explosive. A part of the energy is absorbed by the deformation of the belly. Still the vehicle is subjected to the impulse transmitted by the detonation which may severely injure occupants. The intensity of the impulse is highly dependent on three main parameters which are the degree of saturation of the soil, the nature of the soil in which the explosive is buried and the depth of burial of the charge. Computer simulations should follow the complete process of the explosion, including the early interaction of the charge with the soil, the expansion of the detonation products, the propagation of the shock wave up to the vehicle floor, and the large deformation of the soil projections. The mechanical information transmitted up to the floor level should be sufficiently accurate because the impact on the vehicle is the key target of the simulations. Developing a constitutive soil model is therefore a challenging task. The soil model is visco-plastic with a hardening cap surface, a failure surface to limit shear stresses and a cut off surface against excessive tension. The entire yield surface is smooth so that the plastic strain increments are continuous. A stiffening mechanism is introduced to account for air compression and accommodate the huge stresses in the immediate neighborhood of the charge. The water content of the soil is also taken into account. Two sets of experiments were carried out at DGA TT to serve as a reference for computer simulations. A first campaign involved small quantity of explosive at several depths of burial. The aerial pressures were measured at various heights and compared to simulations. The second set of experiments used a test rig to measure both the deformation of a floor simulating plate and the impulse transmitted by the buried explosion. A range of soil water contents, depths of burial of the explosive, plate thicknesses and stand off distances has been explored. For all the experiments, the sandy gravel STANAG soil defined in AEP 55 of STANAG 4569 has been used. Eulerian simulations were run and fit with these experiments. The roles of the three parts of the yield surface, of the elastic stiffening and plastic hardening mechanisms could be assessed. The initial soil density and the initial cap position were found to have the largest influence on aerial pressures. As for the impulse transmitted to the metallic plate, it was observed to be mostly controlled by the degree of saturation of the soil
Szymkiewicz, Fabien. "Évaluation des propriétés mécaniques d’un sol traité au ciment." Thesis, Paris Est, 2011. http://www.theses.fr/2011PEST1120/document.
Повний текст джерелаThe Soil-Mixing consists in mixing a hydraulic binder into the soil mechanically in order to improve its mechanical properties. Because of its economical as well as its sustainable advantages, this method so far confined to the improvement of compressible or high organic content soils has become an attractive alternative to traditional methods for soil reinforcement, retaining walls (temporary or final), foundations and cutoff walls. But these new applications imply new requirements on the method as well as on the material. Many studies on the subject provide some answers. However, there is no comprehensive parametric study examining both the impact of soil type and the amount of water on the characterization of the Soil-Mixing material and would improve the testing methods and methods for design of structures in Soil-Mixing.Soil-cement mixtures are predominantly composed of soil. The cement will represent at most 30% of the mixture. That is why we have chosen to follow a geotechnical approach rather than the concrete approach for this project.We followed an experimental program based on a laboratory study, realizing mixes called "reference" mixes. Three sand soil and five fine soils were treated by varying each time the quantities of cement and water to observe the influence of particle size, clay content and the amount of water present in the mixes on the resistance of the material, stiffness and failure strain. In addition, soils made from sand and fine soils were reconstituted and treated to study the impact of fines and their nature on the strength of the material.In parallel, monitoring of various projects has enabled us to study the implementation of the method, the homogeneity of the material produced in situ, and to compare the results with those of the parametric study. The results of this work are the creation of abaci connecting the resistance to the cement content and C/E ratio, and a summary table of experimental data of different mechanical properties of the Soil-Mixing material (depending on the nature of the soil), and formulas for granular soils predicting the strength after 7 and 28 days of curing depending on the percentage of fines in the soil and on cement content
Fatras, Christophe. "Etude de la rétrodiffusion altimétrique pour la caractérisation des surfaces et de l'humidité des sols en Afrique de l'Ouest." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30106/document.
Повний текст джерелаThe radar altimetry interferometry satellite SWOT, which is to be launched in 2020, should provide for the first time a global coverage of a close-to-nadir radar altimeter in a few days using the Ka-band. Yet, the use of such a frequency band for continental hydrology is still poorly documented. In particular, the contrast of the backscattering coefficient over soils and over water bodies for nadir and close-to-nadir angles is a major issue. This is the reason for this work. First, the study of the backscattering coefficients from C- and Ku- band altimeters and scatterometers over West Africa has shown that there is a link between the surface soil moistureand the backscattering coefficient. In semi-arid regions, this link is seen through a rise of the backscattering coefficients during the rainy season compared to the dry season. The analysis with ancillary data such as the surface soil moisture and the precipitation estimations has also shown that nadir-looking radars detect more precisely the changes in surface soil moisture compared to side-looking radars. Still with the purpose to better understand the Ka-band surface scattering, poorly documented, two measurement campaigns were led, on the one hand over water surface with controlled roughness, on the other hand over bare soils with monitored roughness and surface soil moisture. In parallel, an altimetry backscattering simulation program has been developed to analyze the effect of a low number of variables on realistic grounds, with the aim of simulating the backscattering coefficient variations. These measurements and simulations were then compared with time series from the satellite altimeter AltiKa, which has been launched in 2013 and works at Ka-band, over different sites representaing the bioclimatic areas of West Africa. It led to a high sensitivity of the Ka-band to changes in the surface soil moisture. It has also been shown that backscattering coefficients at nadir-looking angle from AltiKa over grounds and over water bodies can be similar
Delmont, Tom. "Description des communautés microbiennes du sol par une approche métagénomique." Thesis, Ecully, Ecole centrale de Lyon, 2011. http://www.theses.fr/2011ECDL0048/document.
Повний текст джерелаMicrobial ecology is beginning to interact with metagenomics and many microbiologists are attracted to metagenomics in the hope of discovering novel relationships between microorganisms and/or confirming that work done on isolates applies to the remaining uncultured members of the different ecosystems. With a growing number of available metagenomic datasets, metagenomes can be intensively mined by microbial ecologists in search of previously undetected correlations (both structural and functional). Here, we provide a preliminary exploration of 77 publically available metagenomes corresponding to DNA samples extracted from oceans, atoll corals, deep oceans, Antarctic aquatic environments, Arctic snows, terrestrial environments (sediments, soils, sludges, microbial fuel cell anode biofilms, acid mine drainage biofilms), polluted air, and animal and human microbiomes (human feces, mouse and chicken cecum, and cow rumen). Results show well-defined environmental specificities that emphasize microbial adaptation and evolution capabilities. Unexpected observations were also made for several ecosystems, thus providing new hypotheses about the life style of their microbial communities. Available metagenomes are a gold mine of underexploited information that could be used to explore specific microbial structural and functional relationships. The statistical analysis provided here depends in part on replicates from the different ecosystems. With the continued emphasis on metagenomic sequencing, future analyses should support rigorous statistical treatment. This preliminary metagenomic decryption could represent a pilot-scale test for a future Earth microbiome global comparison
Keraval, Benoît. "Les métabolismes oxydatifs extracellulaires : une nouvelle vision des processus de minéralisation du carbone organique du sol." Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22740/document.
Повний текст джерелаPey, Benjamin. "Contribution de la faune du sol au fonctionnement et à l'évolution des Technosols." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL090N/document.
Повний текст джерелаTechnosols are soils whose properties and pedogenesis are influenced by technical materials which take part in their constitution. The experimental model used here is a constructed Technosol which is deliberately composed of technical materials in a soil profile. The scientific objective is to evaluate the contribution of soil fauna to processes implied in soil functioning and evolution. Experiments in laboratory (cosms) and in climatic conditions (lysimeters, field) are conducted from ultrastructural scale to soil profile scale. Results indicate that (i) constructed Technosol can support soil fauna, (ii) the model of ecosystem engineer: Lumbricus terrestris, by macroporosity and by stables biogenic structures, contribute to the structuration, the aggregation and the decomposition of organic matter of the Technosol, (iii) when several groups of organisms implied in differents soil functions are used, effects are observed on organic matter decomposition. The huge availability of resources in the Technosol allow the presence of soil fauna but its effects and reduce soil fauna interactions which can have effects on soil functioning. A model whose objective is to evaluate effect of Lumbricus terrestris on macroporosity is proposed. In terms of soil engineering, a project of decision support model results of scientific experiences. Soil fauna inoculation in soil engineering could contribute to initiate and accelerate mechanisms of Technosol evolution
Osman, Naoum Jorge. "Étude des populations bactériennes des écosystèmes des sols oligotrophes en utilisant des technologies de séquençage à haut débit." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS196/document.
Повний текст джерела“What microbes are where, and how do they live there” is now an essential question to understand life on Earth, even when comparing seemingly similar ecosystems in different locations. Soil bacterial populations are known to play important roles in biogeochemical cycles, soil maintenance, climatic effects and agriculture. I used pyrosequencing of PCR amplified 16S rDNA from total extracted DNA in order to reveal the bacterial populations living in four different unusual and oligotrophic environments: A. Saline areas are widely distributed on Earth’s and are represented by both saline lakes and saline soils. We examined the bacterial composition of estuary sediments, brackish and sandy soil samples from the Camargue region (Rhône delta in southern France) sampled in two consecutive years. Members belonging to the Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Acidobacteria and Actinobacteria phyla were found principally in saline sediment and soil samples. We found that members from these phyla were associated principally to halophilic bacteria, sulphate reducing bacteria (SRB), nitrate reducing bacteria and coliforms, and that their varying proportions were likely affected by salinity and geographical location. B. Bacterial populations associated with the rhizosphere of plants are known to play essential roles in biogeochemical cycles, plant nutrition and disease biocontrol. We examined the bacterial populations of the rhizosphere of rice (Oryza sativa) growing in the Camargue region in 2013 and 2014. The most abundant bacterial populations were found to be members belonging to the Proteobacteria, Acidobacteria, Chloroflexi and Gemmatimonadetes phyla. The genera members belong these phyla were found to participate in soil biogeochemical processes such as nitrification, denitrification, oxidation, as well as act as biocontrol agents. The bacterial populations were found to significantly vary by geographical location as well by year of collection. C. We examined the surface soils from “Padza de Dapani” on the island of Mayotte off the east coast of Africa, as this region is not a true (hot) desert, but resembles one due to extensive soil erosion. In the acidic, oligotrophic and mineralized soil samples from Mayotte, members of the Actinobacteria, Proteobacteria and Acidobacteria phyla dominated the bacterial populations. Interestingly, members of the genera Acinetobacter, Arthrobacter, Burkholderia and Bacillus were found to be predominant in our samples, as is also observed in hot (Asian) deserts and may play roles in soil mineral weathering, thus helping to understand desertification processes. D. Earth’s arid regions comprise >30% of the continental surface and the oligotrophic soils are subjected to harsh environmental factors such as low average annual rainfall, high UV exposure and large temperature fluctuations. We examined the bacterial populations present in the rhizosphere of pioneer plants and surface soils in the Jizan desert of Saudi Arabia. The most abundant bacterial phyla belonged to the Bacteroidetes, Proteobacteria and Firmicutes phyla that were different between the rhizosphere of plant versus these from surface sand, with the exception of the plant “Panicum Turgidum”, which contain in its rhizosphere high proportions (70%) of members belonging to the Flavobacterium genus
Daoud, Farid Zineddine. "La perméabilité des sols fins compactés." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL056N.
Повний текст джерелаSaenger, Anaïs. "Caractérisation et stabilité de la matière organique du sol en contexte montagnard calcaire : proposition d'indicateurs pour le suivi de la qualité des sols à l'échelle du paysage." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENS010/document.
Повний текст джерелаMountain soils are major reservoirs of carbon (C), potentially vulnerable to climate and land use changes that affect them significantly. However, the great variability of these soils, their limited accessibility and the lack of appropriate measurement tools restrict our knowledge. Today, our comprehension of the biogeochemistry of mountain soils remains very incomplete regarding stocks, chemistry and reactivity of soil organic carbon (SOC). Yet this information is necessary to understand the evolution of soil carbon in the current context of global change. The objectives of this work were (i) to gain a better understanding of the nature, stability and vulnerability of SOC in a mosaic of ecosystems in a calcareous massif in the Alps (Vercors massif), (ii) to search for fast and reliable characterization tools, suitable for the study and monitoring of COS at the landscape scale, and (iii) to propose indicators for the assessment and monitoring of soil quality in mountain regions. As a first step, we tested the application of Rock-Eval pyrolysis for the study of COS at large-scale on a set of ecosystem units. Then, we compared the Rock-Eval approach to two conventional techniques for soil organic matter (SOM) study: the particle-size fractionation of SOM, and the mid-infrared spectroscopy. These coupled analytical approaches allowed us to quantify C stocks across the study area, and explain the stability and the vulnerability of COS at various angles. Factors responsible for the patterns observed in the different eco-units are discussed. This work also confirmed the relevance of the Rock-Eval tool to achieve our previous objectives. Biological approaches allowed us to assess the significance of microbial pool in these soils. Finally, indices assessing the status of SOM (SOC storage, soil fertility, vulnerability COS) were proposed and constituted interesting management tools for decision-makers
Jahangir, Emad. "Phénomènes d'interaction sol-structure vis-à-vis de l'aléa retrait-gonflement pour l’évaluation de la vulnérabilité des ouvrages." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL088N/document.
Повний текст джерелаClayey soils can present large volumetric deformations in response of water content change. This phenomenon of shrinkage and swelling of clayey soils is recognized as a costly natural hazard throughout the world. In France, this cost is reported between 1988 and 2007 to 5 million Euros, ranking in second class of the French natural hazards in terms of cost of damage after the floods. The individual masonry buildings with shallow foundations are the most affected by this phenomenon that causes a differential settlement of the building leading to cracks in facades and structural elements, especially in unreinforced masonry elements.The objective of this thesis was to study the vulnerability of the building, against the shrink-swell hazard through an analysis of soil-structure interaction. This work was focused on three major points: - Hydro-mechanical behavior of clay soils - Soil-structure interaction - Evaluation of structural damage.The hydro-mechanical behavior of clay soils was considered by the concept of state surface and integrated into a soil-structure interaction model, based on the Winkler model, with increasingly complex approaches: 1D, 2D and 3D by modeling the building behavior respectively by a spring system, the beam element and the plate element. These models of soil-structure interaction are able to calculate the relative deflection of the building, according to the values of imposed suction, mechanical properties of the structure and hydro-mechanical properties of the soil. The relative deflection of the building is then compared to threshold values of the classical damage categories to assess the building damage.Finally a feasibility study was conducted on the development of vulnerability curves adapted to the problem of shrinkage – swelling of clayey soils. These curves represent the average of structural damage versus suction, for each type of building. These curves were developed based on a classification of expansive soils and a building typology outcome from databases of affected buildings. The average damage is calculated by the Monte-Carlo method, taking into account the variability of the building parameters
Vincent, Quentin. "Étude des paramètres abiotiques, biotiques et fonctionnels, et de leurs interactions dans des sols délaissés." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0015/document.
Повний текст джерелаDue to industrial activities intensification, large surfaces of degraded soils, with low fertility and sometimes contamination, are derelict. In the context of land depletion and economic pressure, the rehabilitation of these derelict anthropogenic soils could be a key issue. However, these derelict soils needs to be better characterized before to consider their potential use. Soil quality studies rarely take into account the biodiversity and the biological functioning. Thus, the aim of this PhD work was to characterize derelict soils by considering their abiotic, biotic and functional parameters. To this end, six derelict strongly anthropogenic soils from north-eastern France, resulting from different industrial activities, were studied in situ and in laboratory. Several biotic components (bacteria, fungi, mesofauna, macrofauna and flora) were studied to have an almost complete approach of the soil biodiversity. Taxonomical and functional (trait-based approach) study of biodiversity was performed for fungi, meso- and macrofauna. Moreover, the in situ evolution over time of abiotic and biotic parameters was taken into account in one of the six studied derelict soils. Lastly, biotic interactions between a species of Collembola, of arbuscular mycorrhizal fungi and of herbaceous plant were studied in two derelict soils, in a growth chamber. We showed that derelict soils were characterized by a significant biodiversity, comparable case to case with other kinds of soils like forest, grassland or crop. Nevertheless, differences in terms of density, richness and taxonomical and functional structure community were observed between soils and depend on considered biotic group. These differences were notably linked with contrasting physico-chemical parameters between soils. Thus, a compost-amended constructed soil was the less disturbed among the six studied soils, in contrast with a heavy metal-contaminated constructed soil. We showed that abiotic parameters, notably biotic parameters, evolved quickly (within one year) in the metal-contaminated constructed soil. In the two derelict soils where interactions between Collembola and mycorrhizal fungi were studied, biotic interactions were affected by several parameters like soil volume, time of interaction, indigenous microflora presence etc. Finally, we have shown that these derelict soils support ecosystems services such as biodiversity reserve and could be functional, allowing potential re-use
Tardy, Vincent. "Lien entre la diversité microbienne, la stabilité des communautés microbiennes et le turnover des matières organiques du sol." Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOS081/document.
Повний текст джерелаSoil microbial communities act as important agents of the biological soil functioning, particularly through their involvements in the transformations of biogeochemical cycles (C, N, P…). In agro-ecosystems, the diversity of these communities is affected by perturbations associated to agricultural practices, and the significance of these modifications in terms of preservation of biological functioning and sustainability of agricultural systems has emerged as a central issue in the environmental sciences. Whereas the role of biodiversity has been well studied for macroorganisms, in particular for plants; the biodiversity/activity relationship is still largely unknown for soil microorganisms. However, in the current agro-ecological movement, this knowledge is needed to define new agricultural practices including a best management of microbial diversity for the sustainable use of agro-ecosystems. In this context, the objective of this Phd was to test the significance of microbial diversity for the stability (resistance/resilience) and the activity of microbial community (bacteria and fungi) involved in the turnover of soil organic matter, a major function for soil fertility, environment quality and global changes. From an experimental point of view, these issues were addressed by coupling laboratory with field experiments. In a first work, by manipulating microbial diversity in laboratory condition, we have shown that the stability of both microbial genetic structure and activity in response to different perturbations is positively linked to microbial diversity (i.e. number of species). This link was then validated by a sampling based on a field experiment that allowed us to demonstrate that (i) the soil microbial diversity can be modulated (increased or decreased) depending the intensity of land use management, and (ii) the mineralization of organic matter is more intense in the soil with the highest level of diversity. Finally, thanks to an experiment carried out in the field (SOERE-ACBB, Lusignan), we showed that the response of bacterial and fungal communities to wheat residues supply in terms of successions of microbial populations and activities of organic matter mineralization depends on the soil management history. These works provide new insights into the significance of microbial diversity (richness, composition) for the stability and the activity of communities involved in the soil organic matter turnover. They also suggest that the modulation of the diversity of soil microbial communities by agricultural practices, past or present, can significantly affect the turnover of soil organic matter
Basmaji, Bakri. "Développement d’un modèle analytique d’interaction sol-structure pour l'étude du comportement mécanique des structures soumises à un mouvement de terrain : influence des déformations de cisaillement et de la plasticité." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0290/document.
Повний текст джерелаThis work is a continuation of the research work conducted in the Géoressources Laboratory and INERIS since several years. It concerns the assessment of the vulnerability of masonry structures influenced by natural or induced ground movements. The origins of the movement are may be, mining subsidence, tunneling, and shrinkage-swelling of clayed ground. The objective of the thesis is to develop an analytical model to evaluate the differential settlement of a structure in relation to the free field ground movement and given a set of phenomena: soil-structure interaction, influence of shear deformations in the structure and the ground, influence of non- linearities induced by the ground yielding. The soil was modeled by Pasternak elements to take into account the influence of shear deformations in the soil, while the building is modeled by the Euler-Bernoulli beam and by the beam of Timoshenko. The possibility of having a gap under the building was also taken into account. The deflection transmission ratio is then calculated and plotted according to are lative stiffness ratio which depend on both the structure and the soil stiffness A numerical model is also developed and results are compared with those of the analytical model. Other results of several numerical and experimental models principally developed at the University of Cambridge are also used for this comparison. Results show significant consistence between all these results. This demonstrates the significance of the analytical soil-structure model developed in this thesis
Nowamooz, Hossein. "RETRAIT/GONFLEMENT DES SOLS ARGILEUX COMPACTES ET NATURELS." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2007. http://tel.archives-ouvertes.fr/tel-00331856.
Повний текст джерелаL'ensemble des résultats expérimentaux permet de déterminer les surfaces de charge : la limite de séparation de micro/macro (Lm/M) ; la surface de chargement-effondrement (LC) et la surface de comportement saturé (SCS). La succion limite entre la micro- et la macrostructure (Lm/M) dépend parfaitement de la structure interne et du diamètre qui délimite les deux familles de pores. L'évolution de la pression de préconsolidation en fonction de la succion imposée est présentée par la surface LC. Les courbes de compressibilité sous différentes succions convergent vers la courbe correspondant à l'état saturé sous de fortes contraintes appliquées. La pression à partir de laquelle, le sol continue son chemin sur la courbe du comportement normalement consolidé est appelée la pression de saturation (Psat). Plus la succion imposée est élevée, plus la charge nécessaire pour atteindre cette pression de saturation est importante. La surface SCS présente la variation de la pression de saturation en fonction de la succion imposée. Nous pouvons considérer que les surfaces de charge SCS et LC sont uniques pour les sols denses cependant elles se superposent à la fin des cycles de succion pour les sols lâches. Les cycles hydriques augmentent aussi la limite (Lm/M) entre la micro- et la macrostructure pour les deux sols.
Wells, John. "Expériences sur les impacts liquide-solide et le soulèvement de particules par un tourbillon annulaire : applications à l'érosion des sols et au transport des sédiments." Grenoble 1, 1992. http://www.theses.fr/1992GRE10037.
Повний текст джерелаAssemien, Embi Féline Laurenza. "Impact de pratiques agricoles conventionnelles et innovantes sur la fertilité des sols et les acteurs microbiens impliqués dans la zone de savanes humides de Côte d’Ivoire." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1103/document.
Повний текст джерелаIn West Africa, humid savanna soils are characterized by extremely low concentrations of organic matter, mineral nitrogen, phosphorus and basic cations, which limit primary production. We analyzed how particular changes in land-uses can influence the functioning and fertility of soils, to support the production of agroecosystems in this savanna zone. We compared six land-use types at 9 experimental plots across a landscape: traditional slash-and-burn; conventional chemical fertilization; and innovative use of mulching (tested with or without inserting legumes in the crop rotation). Bare soil was also considered as a reference situation. Soil was sampled on the 54 sub-plots, before and 3 times after treatment inception. We surveyed seven soil enzyme activities (denitrification, nitrification, β glucosidase, N-acetyl-β-D-glucosaminidase, acid and alkaline phosphatase, dehydrogenase), key soil variables (moisture, organic C, mineral and total N, pH, and available P) and the abundances and diversity of microbial communities involved in the N cycle (bacterial and archaeal ammonia oxidizers; Nitrobacter; Nitrospira; and nirS-, nirK- and nosZ-like denitrifiers). Our results showed that (i) C. org, K, Mg and soil enzymes activities decreased with soil depth, reflecting a low rate of nutrient accumulation in soil depth. In contrast, fallow periods (0 to 10 years) did not significantly affect the majority of soil properties, excepted soil Ntot and K, which were high in old fallows. In addition, C. org decreased as a function of the fallow period, but Mg follow-up an inverse trend; (ii) the land use type strongly affects most soil enzymatic activities and the microbial communities involved in nutrient cycling; (iii) innovative mulching practices have a positive impact on soil characteristics and microbial communities, thereby maintaining the maintenance of soil fertility and the sustainability of agricultural production in the long term. According to our results, the practice of mulching, possibly with the insertion of legumes, could be less expensive and more appropriate to progressively and sustainably increase nitrogen availability in these agro-ecosystems
Li, Zhong-Sen. "Etudes des propriétés hydromécaniques des sols argileux non saturés proches de la saturation." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2015. http://www.theses.fr/2015ECAP0023/document.
Повний текст джерелаThis thesis present an experimental study of an unsaturated clayey soil close to saturation, whose degree of saturation is generally above 70%.After characterizing the physical and mechanical properties of the material, several experimental methods were used to study the behaviour and some pathologies of the compacted soil, such as rutting and quilting.A systematic study of the behaviour of the compacted soil on drying-wetting paths starting from different initial states was carried out, completed by suction measurements using filter-paper and psychrometer. Mercury intrusion porosimetry tests gave an insight of the soil microstructure.The thesis also addressed the question of the pore pressure variations of the compacted soil on undrained triaxial path using the axis-translation technique, where some improvements and modifications of the testing device were proposed
Iqbal, Javed. "Contribution à l'analyse des effets macroscopiques de l'interaction structure-sol-structure par modélisation simplifiée en éléments spectraux." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU030/document.
Повний текст джерелаThis work is a contribution to investigations on the effects of dynamic soil-structure interaction on the seismic motion of both ground surface and buildings. It is based mainly on a numerical approach using the spectral element method and a simplified representation of buildings with "block models", calibrated however on a comparison with various sets of instrumental data. One of the main goals is to set the frame for a relevant macroscopic modeling of SSI and SSSI effects on ground and structural dynamic response. After a presentation of the background theoretical framework of soil-structure interaction and the main modeling approaches, various examples from Euroseistest / Volvi (Greece), Grenoble Ile Verte towers (France) and Anchorage (Alaska) are investigated in detail to identify the main modeling issues and to propose a procedure to best tune the model and its parameters to the actual behavior. It includes a discussion on the main relevant macroscopic dynamic characteristics to fit (frequency, damping and rocking ratio), and on the way to use "block models", i.e., models consisting of blocks full of fictitious material, to satisfactorily reproduce the macroscopic response of actual buildings having highly variable slenderness ratios, with frames or shear walls. A special attention is devoted to the "block-modeling" of buildings with non-symmetrical dynamic properties and Timoshenko beam like behavior, through the introduction of material heterogeneities within the spectral elements of block models, while keeping unchanged the geometrical cross-section. It also includes a thorough comparison on the major differences between 2D and 3D models and their physical origins: for long buildings with aspect ratios (length over width ratio) lower than 6, 2D models are shown un-conservative, as they tend to significantly overestimate the damping and rocking ratios. This work also includes a large part on the effects of Structure-to-Structure interaction through the soil. Various cases are considered, from the 2 building case in 2D and 3D geometries to an idealized, densely urbanized 3D area, with various types of excitations (pull-out, surface or deep source). Effects of inter-building distance and frequencies are investigated. The general trend is a reduction of the ground and building motion around the fundamental frequency, with however opposite effects for the first higher mode. The reduction effects are found of particular importance because of the shielding effects of building clusters for surface waves
Dousset, Sylvie. "Évaluation des potentialités de lessivage de la terbuthylazine et de l'atrazine dans trois sols de la région Centre." Vandoeuvre-les-Nancy, INPL, 1994. http://docnum.univ-lorraine.fr/public/INPL_T_1994_DOUSSET_S.pdf.
Повний текст джерелаBelkacem, Saïd. "Étude de la restauration des sols acides soumis à de forts apports acides : effet des formes et doses d'amendements sur le fonctionnement d'un sol acide forestier." Nancy 1, 1993. http://www.theses.fr/1993NAN10282.
Повний текст джерелаDupré-Camus, Françoise. "Transfert des radioéléments des sols aux végétaux : conditionnement des facteurs de transfert par la nature des sols, les formes chimiques et le mode d'apport." Aix-Marseille 2, 1988. http://www.theses.fr/1988AIX22025.
Повний текст джерелаBarataud, Fabienne. "Analyse physique des transferts hydriques dans un sol forestier à plusieurs échelles spatiales." Vandoeuvre-les-Nancy, INPL, 1997. http://www.theses.fr/1997INPL026N.
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