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Characterization of the Dagorda claystone in Leiria, Portugal, based on laboratory tests

Veiga, Anabela
Fonte: Springer Publicador: Springer
Tipo: Parte de Livro
ENG
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The Hetangian Dagorda claystone Formation occupies the core of a diapir outcropping in part of the city of Leiria, exhibiting a complex geological structure. The geological and geotechnical characterization is presented based in field observation and laboratory tests allowing to conclude that the Dagorda clay soils exhibit an unfavourable behaviour for urban occupation, due to the presence of expansive clay minerals. When partially saturated these soils can lead to cracking of walls and floors, or even to endanger the stability of buildings, if they have not been strengthened to resist to expansive soil. The presence of soluble minerals, mainly gypsum and seldom halite, can allow the formation of voids and eventually the deformation or collapse of the ground. Suitable safety procedures, in order to prevent hazards should be used.

"Utilização do resíduo proveniente do acabamento e manufatura de mármores e granitos como matéria-prima em cerâmica vermelha" ; USE OF RESIDUES PROCEEDING FROM MARBLES AND GRANITES FINISHING AND MANUFACTURING PROCESSES AS RAW MATERIAL FOR STRUCTURAL CERAMIC.

Mello, Roberta Monteiro de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/04/2006 PT
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A utilização da lama residual de marmoraria em cerâmica vermelha foi colocada em prática visando à diminuição do impacto ambiental, causado tanto pelo descarte da lama como também pela quantidade de argila extraída no setor cerâmico. Foram coletadas amostras em 12 marmorarias localizadas na Grande São Paulo. No entanto, apenas as amostras de quatro foram selecionadas para serem incorporadas, levando em consideração suas características distintas. O argilito foi a matéria-prima escolhida para confecção da massa padrão de cerâmica vermelha, devido à sua grande utilização no setor. Tanto as amostras a serem incorporadas, quanto o argilito, foram caracterizados por meio de análise granulométrica, análise química por fluorescência de raios X e análise mineralógica por difração de raios X; além de análises segundo à norma NBR 10004 nas lamas. Após a caracterização das matérias-primas, foi aplicado às misturas o ensaio de plasticidade; em seguida, confeccionados corpos-de-prova com diversos teores de lama incorporada, os quais foram queimados e submetidos a ensaios tecnológicos, como resistência mecânica, absorção de água, porosidade, massa específica aparente e retração, dilatação do material seco e microscopia eletrônica de varredura. Os resultados demonstraram a viabilidade de aproveitamento destas lamas...

Origem vulcânica para o tonstein da jazida do Faxinal (RS) : estudos mineralógicos, petrográficos e de palinofácies

Simas, Margarete Wagner
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
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Análises mineralógicas, petrográficas e de palinofácies são registradas em um leito de tonstein associado a camadas de carvão na Jazida do Faxinal, Rio Grande do Sul, Brasil. A integração dos dados revestiu-se de grande importância para atribuir uma origem vulcânica para este argilito caolinítico. O tonstein é uma rocha quase monominerálica, composta predominantemente por caolinita antigênica. Dispersos na massa caolinítica ocorrem os minerais piroclásticos: paramorfos de quartzo-ß bipiramidais euédricos, “splinters” de quartzo transparente, zircão idiomórfico, apatita euédrica, alanita e pseudomorfos de sanidina, os quais são considerados como uma suíte restrita de minerais vulcânicos de tonsteins distais que preservaram durante a diagênese. Os minerais primários e suas feições texturais, bem como as relações de campo, indicam uma origem vulcânica de queda para essa camada. O estudo de palinofácies, inédito para este tipo de rocha, evidenciou uma composição diferenciada da matéria orgânica estruturada ao longo do perfil do tonstein. Análises estatísticas do querogênio de diferentes níveis da camada de tonstein indicaram altas percentagens de fitoclastos (xilema e epiderme) associados à menor representatividade de palinomorfos. Análises microestratigráficas destes níveis demonstraram que a saturação e a precipitação dos palinomorfos foram altamente influenciadas pelo intenso processo de queda de cinzas. O nível basal caracteriza-se por densos aglomerados de esporos e polens...

Matéria-prima da formação Corumbataí na região do pólo cerâmico de Santa Gertrudes, SP, com características naturais para fabricação de argila expandida

Moreno, M. M. T.; Zanardo, A.; Rocha, R. R.; Roveri, C. D.
Fonte: Associação Brasileira de Cerâmica Publicador: Associação Brasileira de Cerâmica
Tipo: Artigo de Revista Científica Formato: 342-348
POR
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Estudou-se um material da base da Formação Corumbataí, proveniente de uma mineração de argila, que apresenta restrições de uso em cerâmica devido à sua dureza e, principalmente, ao alto conteúdo de matéria orgânica. Verificou-se que o material apresenta características naturais ótimas para a fabricação de argila expandida diretamente a partir de fragmentos de rocha, mostrando comportamento piroplástico com expansão significativa se submetido à queima rápida. A caracterização da matéria-prima e do produto foi realizada mediante análise de carbono orgânico, difração de raios X, microscopia ótica e testes de queima. Foram determinadas as condições de queima para obter argila expandida utilizando forno de queima rápida e forno a rolos, ambos de laboratório, obtendo corpos com densidade variável (que podem chegar a valores menores que 0,5 g.cm-3) até o limite de expansão. Esta densidade é obtida devido à formação de poros fechados e uma película externa vítrea, que proporcionam uma resistência mecânica alta aos fragmentos expandidos.; This paper refers to the study of the material of the base of the Corumbataí formation (Parana Basin...

Carta geológico-geotécnica como subsídio a elaboração de cartas de sensibilidade ambiental, a derrames de petróleo e derivados, na região do oleoduto Guararema-São José dos Campos, Vale do Paraíba (SP)

Oliveira, Érica Mantovani de
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 99 f. : il., tabs., quadros, fots. 1 mapa
POR
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Pós-graduação em Geociências e Meio Ambiente - IGCE; A presente pesquisa propôs a elaboração da carta geológico-geotécnica na região do oleoduto “Guararema – São José dos Campos” com o intuito de subsidiar a elaboração de cartas de sensibilidade ambiental ao derramamento de petróleo e derivados, no Vale do Paraíba. A área estudada localiza-se no leste do estado de São Paulo e caracteriza-se pelo contraste de relevo entre as Colinas Sedimentares da Bacia de Taubaté e os Morros Cristalinos das serras do Mar e Mantiqueira; pela diversidade litológica (gnaisses, xistos, granitos, arenitos, argilitos, siltitos, entre outras); pela presença do rio Paraíba do Sul, da represa de Santa Branca e de Áreas de Proteção Ambiental. Esta área é cortada pelo duto que parte do Terminal de Guararema, seguindo até a Refinaria de São José dos Campos e já foi alvo de acidentes relacionados com dutovias (1987, 1994 e 1998). Tais acidentes podem ocorrer novamente, ameaçando a qualidade ambiental da área. As cartas de sensibilidade ambiental. podem auxiliar na redução das conseqüências ambientais do vazamento e tornar eficientes os esforços de contenção e limpeza/remoção, além de servir como suporte técnico a outras atividades socioeconômicas e de gestão ambiental. O método utilizado para a execução do trabalho foi composto por: 1. Pesquisa Bibliográfica; 2. Preparação de Base Cartográfica; 3. Compartimentação do Terreno...

Mud volcanism in the Gulf of Cadiz: results from the TTR-10 cruise

Pinheiro, LM; Ivanov, MK; Sautkin, A; Akhmanov, G; Magalhaes, VH; Volkonskaya, A; Monteiro, JH; Somoza, L; Gardner, J; Hamouni, N; Cunha, MR
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
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A new deep water mud volcano field (between 2000 and 3500 in water depth) was discovered in the deep South Portuguese margin, as well as several new mud volcanoes in the South Spanish and Western Moroccan margins of the Gulf of Cadiz, during the TTR-10 (Training Through Research, UNESCO/IOC) cruise, in July/August 2000. This work followed the discovery of a large mud volcano field in the Gulf of Cadiz, first investigated during the TTR-9 cruise [Gardner (2001) Geophys. Res. Lett. 28, 339-342; Kenyon et al. (2000) IOC, Technical series no. 56]. The discoveries were made based on a SEAMAP side-scan sonar mosaic and multibeam. bathymetry (SEABEAM) collected in the area by the Naval Research Laboratory (NRL), Washington, DC, USA, in 1992, kindly released for this purpose. Single-channel seismics, long-range side-scan sonar (OKEAN), TV-controlled grab, hull-mounted 3.5-kHz profiler and coring were used to investigate several seafloor features observed on the side-scan sonar imagery, in the South Iberia, Spanish and Moroccan margins of the Gulf of Cadiz, which were confirmed to be mud volcanoes. The typical structures related to fluid venting in the Gulf of Cadiz are essentially represented by conical mud volcanoes with diameters ranging from several tens of meters to 4 kin and heights that can reach 200 in. Some of these structures appear to be aligned along major conjugate NE-SW and NW-SE trending faults that can be identified on the side-scan sonar imagery. The new field discovered in the South Portuguese margin is the deepest in the Gulf of Cadiz area and includes three new mud volcanoes - Bonjardim...

Osmium isotope evidence for a large Late Triassic impact event

Sato, Honami; Onoue, Tetsuji; Nozaki, Tatsuo; Suzuki, Katsuhiko
Fonte: Nature Pub. Group Publicador: Nature Pub. Group
Tipo: Artigo de Revista Científica
Publicado em 16/09/2013 EN
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Anomalously high platinum group element concentrations have previously been reported for Upper Triassic deep-sea sediments, which are interpreted to be derived from an extraterrestrial impact event. Here we report the osmium (Os) isotope fingerprint of an extraterrestrial impact from Upper Triassic chert successions in Japan. Os isotope data exhibit a marked negative excursion from an initial Os isotope ratio (187Os/188Osi) of ∼0.477 to unradiogenic values of ∼0.126 in a platinum group element-enriched claystone layer, indicating the input of meteorite-derived Os into the sediments. The timing of the Os isotope excursion coincides with both elevated Os concentrations and low Re/Os ratios. The magnitude of this negative Os isotope excursion is comparable to those found at Cretaceous–Paleogene boundary sites. These geochemical lines of evidence demonstrate that a large impactor (3.3–7.8 km in diameter) produced a global decrease in seawater 187Os/188Os ratios in the Late Triassic.

Chondrites isp. Indicating Late Paleozoic Atmospheric Anoxia in Eastern Peninsular India

Bhattacharya, Biplab; Banerjee, Sudipto
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 30/01/2014 EN
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Rhythmic sandstone-mudstone-coal succession of the Barakar Formation (early Permian) manifests a transition from lower braided-fluvial to upper tide-wave influenced, estuarine setting. Monospecific assemblage of marine trace fossil Chondrites isp. in contemporaneous claystone beds in the upper Barakar succession from two Gondwana basins (namely, the Raniganj Basin and the Talchir Basin) in eastern peninsular India signifies predominant marine incursion during end early Permian. Monospecific Chondrites ichnoassemblage in different sedimentary horizons in geographically wide apart (~400 km) areas demarcates multiple short-spanned phases of anoxia in eastern India. Such anoxia is interpreted as intermittent falls in oxygen level in an overall decreasing atmospheric oxygenation within the late Paleozoic global oxygen-carbon dioxide fluctuations.

Estratigrafia de sequências do intervalo aptiano ao albino na Bacia do Araripe, NE do Brasil; Estratigrafia de sequências do intervalo aptiano ao albino na Bacia do Araripe, NE do Brasil

Rojas, Fabio Enrique Malagon
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Geodinâmica e Geofísica; Geodinâmica; Geofísica Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Geodinâmica e Geofísica; Geodinâmica; Geofísica
Tipo: Dissertação Formato: application/pdf
POR
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This study has as a main objective to make a detailed stratigraphic analysis of the Aptian-Albian interval in the east part of Araripe Basin, NE of Brazil which correspond, litostratigraphically, to Rio Da Batateira, Crato, Ipubi and Romualdo formations. The stratigraphic analysis was based on three different stages, the 1D, 2D and 3D analysis; these ones were adapted to the sequence stratigraphy concepts in order to create a chronostratigraphic framework for the study area within the basin. The database used in the present study contains field and well information, wells that belong to Santana Project, carried out by the Ministério de Minas e Energia- DNPM- CPRM from 1977 to 1978. The analysis 1D, which was done separately for each well and outcrop allowed the recognition of 13 sedimentary facies, mainly divided based on predominant litologies and sedimentary structures. Such facies are lithologically represented by pebble, sandstones, claystones, margas and evaporates; these facies are associated in order to characterize different depositional systems, that integrate from the continental environment (fluvial system and lacustre), paralic system (delta system and lagunar) to the marine environment (shelfenvironment). The first one...

Proterozoic turbiditic depositional system (Tanami Group) in the Tanami region, northern Australia, and implications for gold mineralisation

Lambeck, A.; Hatch, K.; George, A.; Cross, A.; Huston, D.; Meixner, T.
Fonte: Taylor & Francis Ltd. Publicador: Taylor & Francis Ltd.
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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Sedimentological interpretation of outcrop and drillcore, integrated with previously published seismic interpretation and regional chemostratigraphy, is used to establish a depositional model for goldbearing Paleoproterozoic rocks of the Tanami region. Analyses of the Dead Bullock Formation and Killi Killi Formation of the Tanami Group form a basis for future correlations across northern Australia. Poorly exposed Paleoproterozoic sandstone, siltstone and claystone of the Killi Killi Formation record development of a deep-water, basin-floor turbidite system composed of channelised sandy lobes with muddy lobe fringes. The sediment source was located to the northwest. Underlying the Killi Killi Formation are the poorly exposed dark claystones of the upper Dead Bullock Formation, forming a condensed section. We interpret that this depositional system was an important control on gold mineralisation in both the Killi Killi Formation and the underlying Dead Bullock Formation of the Tanami Group. Gold deposition is enhanced within the Dead Bullock Formation where crustal faults intersect claystone facies. Similar facies in the Killi Killi Formation may also host gold mineralisation. Deep exploration holes at the Titania and Old Pirate prospects could potentially intersect the stratigraphically underlying gold-bearing claystones of the Dead Bullock Formation.; A. Lambeck...

Basin analysis and the geochemical signature of Paleoproterozoic sedimentary successions in northern Australia : constraints on basin development in respect to mineralisation and paleoreconstruction models.

Lambeck, Alexis
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2012
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Secular changes in the characteristics of sedimentary basins and their associated mineral deposits in Proterozoic Australia are directly related to the evolving global tectonic regimes and global changes in atmospheric and oceanic redox states. Identifying these secular changes provides critical information to assist in applying first pass techniques for regional exploration in Australia. The break-up and formation of the Nuna supercontinent is recorded within sedimentary basins within Proterozoic Australia. Sedimentary basins deposited between 1910 Ma and 1810 Ma formed during the Nuna supercontinent amalgamation and host orogenic gold mineralisation, whereas those deposited between 1710 Ma ─ 1575 Ma are directly associated with the break-up of Nuna and host lead-zinc mineralisation. Sediments in northern Australia deposited during the Nuna amalgamation, and before the Great Oxidation Event, consist of fine-grained iron-rich/mafic mudstones and siltstones which are geochemically characterised by high FeO contents, high Cr/Th and low Th/Sc values. This sedimentary assemblage includes the gold-bearing succession of the Dead Bullock Formation, Tanami region and Koolpin Formation, Pine Creek Orogen. This contrasts with the regionally overlying stratigraphy...

Hydrogeologische Erkundung toniger Festgesteine am Beispiel des Opalinustons (Unteres Aalenium)

Hekel, Uwe
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Buch (Monographie)
DE
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Im Rahmen des Forschungsprojektes "Gebirgseigenschaften mächtiger Tonsteinserien" des Geologischen Landesamtes Baden-Württemberg wurden auf 6 repräsentativ ausgewählten hydrogeologischen Versuchsfeldern im Ausstrich des Opalinustons (al1) am Rande der Schwäbischen Alb 18 tiefe und 29 flachere Kernbohrungen niedergebracht. Zur Messung der Gebirgsdurchlässigkeit wurden zahlreiche Bohrlochtestmethoden erprobt. Diese hydraulischen Bohrlochtests wurden von hydrogeologischen Feldmethoden sowie der Bestimmung von Gesteinsparametern an Kernproben und der Untersuchung zahlreicher Wasserproben ergänzt. Es wird ein hydrogeologisches Untersuchungsprogramm für Deponiestandorte in tonigen Festgesteinen vorgeschlagen, das geeignete und unter wirtschaftlichen Gesichtspunkten sinnvolle Untersuchungsmethoden beinhaltet. Zur Vorerkundung potentiell wasserwegsamer Klüfte eignen sich optische und akustische Bohrlochmeßverfahren sowie eine aus kurzen Pulse-Tests bestehende Squeeze-Test-Serie. Quantitative Aussagen über die Gebirgsdurchlässigkeit im Opalinuston können mit Doppelpackertests (Pump-, Slug-, Drill-Stem und Pulse-Tests) getroffen werden. Als günstige Alternative zu diesen konventionellen Testarten eignet sich das Fluid-Logging- Verfahren zur teufengenauen Lokalisierung und Quantifizierung von Kluftzuflüssen. Zur Messung der Durchlässigkeit in der ungesättigten Zone werden modifizierte Injektionstests eingesetzt. Zur Auswertung der hydraulischen Tests werden verschiedene Aquifermodelle für den Opalinuston diskutiert sowie konventionelle und neuere Verfahren beschrieben. Neben den Bohrlochtestmethoden werden Durchführung und Ergebnisse von seismischen und konventionellen hydrogeologischen Verfahren wie Pumpversuche...

Boundary between Soil and Saprolite in Alisols in the South of Brazil

Pedron,Fabrício de Araújo; Oliveira,Rodrigo Bomicieli de; Dalmolin,Ricardo Simão Diniz; Azevedo,Antonio Carlos de; Kilca,Ricardo Vargas
Fonte: Sociedade Brasileira de Ciência do Solo Publicador: Sociedade Brasileira de Ciência do Solo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
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Despite numerous studies conducted on the lower limit of soil and its contact with saprolite layers, a great deal of work is left to standardize identification and annotation of these variables in the field. In shallow soils, the appropriately noting these limits or contacts is essential for determining their behavior and potential use. The aims of this study were to identify and define the field contact and/or transition zone between soil and saprolite in profiles of an Alisol derived from fine sandstone and siltstone/claystone in subtropical southern Brazil and to subsequently validate the field observations through a multivariate analysis of laboratory analytical data. In the six Alisol profiles evaluated, the sequence of horizons found was A, Bt, C, and Cr, where C was considered part of the soil due to its pedogenetic structure, and Cr was considered saprolite due to its rock structure. The morphological properties that were determined in the field and that were different between the B and C horizons and the Cr layer were color, structure, texture, and fragments of saprolite. According to the test of means, the properties that support the inclusion of the C horizon as part of the soil are sand, clay, water-dispersible clay, silt/clay ratio...

Fatores condicionantes na gênese dos argilominerais dos folhelhos negros e pelitos associados da formação Irati no norte da bacia do Paraná

Anjos, Camila Wense Dias dos
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Tese
PT_BR
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Tese (doutorado)—Universidade de Brasília, Instituto de Geociências, 2008.; A Formação Irati (Permiano) apresenta uma ampla distribuição na Bacia do Paraná, estendendo-se desde os estados de Goiás e Mato Grosso, ao norte, até o Rio Grande do Sul. Esta unidade encontra-se frequentemente intrudida por sills de diabásio, cujo calor altera a mineralogia inicial das rochas sedimentares. A geometria heterogênea da bacia na época de deposição propiciou o desenvolvimento de diferentes fácies sedimentares nessa unidade, favorecendo a deposição de rochas terrígenas ao sul da bacia e carbonáticas e evaporíticas ao norte. No norte da bacia, área de estudo desta tese, seis fácies sedimentares foram reconhecidas na Formação Irati: Fácies Carbonática Dolomítica, Fácies Pelítica Inferior, Fácies Carbonática Oolítica, Fácies Pelítica Superior, Fácies Estromatolítica e Fácies Carbonática Rosada. As quatro primeiras fácies ocorrem em toda borda norte da bacia, e as duas últimas aparecem somente na região de Alto Garças. A composição mineralógica dos pelitos dessa região, assim como as feições sedimentares, distinguem-se de seus equivalentes nas demais regiões da bacia. Os folhelhos negros e os níveis de argilito verde intercalados são anomalamente formados por Mg- e Fe-esmectitas...

Testing the Gippsland zonation in northern Australia: palynostratigraphical analysis of a 23 Ma 40 Ar/ 39 Ar dated claystone from Toowoomba, southeast Queensland

Macphail, Michael; Gibson, Dave
Fonte: Taylor and Francis Inc. Publicador: Taylor and Francis Inc.
Tipo: Artigo de Revista Científica
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The spore-pollen zonation developed for the Gippsland Basin, southeast Australia, is widely used to date Paleogene-Neogene terrestrial sediments elsewhere in Australia. Microfloras preserved in an argon-40 ( 40Ar)/argon-39 (39Ar) dated 23 Ma claystone on

A laboratory investigation of thermally induced pore pressures in the Callovo-Oxfordian Claystone

Mohajerani, Mehrdokht; Delage, Pierre; Sulem, Jean; Monfared, Mohammad; Tang, Anh-Minh; Gatmiri, Behrouz
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/03/2013
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In the framework of research into radioactive waste disposal, it was decided to investigate the thermally induce pore pressure occurring in the Callovo-Oxfordian claystone, a possible host rock in which the ANDRA underground laboratory of Bure (East of France) has been excavated. Thermal pore pressures appear in low permeability soils and rocks because the thermal expansion coefficient of water is significantly higher than that of the solid grains (Campanella and Mitchell; 1968 [1], Ghabezloo and Sulem; 2009 [2]). This phenomenon has clearly been observed in various in-situ heating tests conducted in Opalinus claystone in the Mont-Terri Underground Research Laboratory (URL) in Switzerland (HE-D test) and in Callovo-Oxfordian (COx) claystone in the Bure URL in France (TER test, Wileveau and Su; 2007 [3]) The processes of coring, transportation, storage and specimen trimming induce some desaturation in the sample. Due to the very low permeability (10-20 m2) of the COx claystone, a long period of time is necessary to properly resaturate the sample, a mandatory condition to satisfactorily investigate thermal pressurisation. Particular emphasis was hence put on the previous saturation procedure that was carried out under in-situ effective stress condition. Thermal pressurization has been investigated by performing undrained heating tests while measuring pore pressures changes in a specially adapted thermal isotropic compression cell. Special care was devoted to calibration procedures to account for the effects of the system on the pore pressure measurements. The thermal pressurization coefficient measured appeared to change with temperature...

The application of high-resolution 3D seismic data to model the distribution of mechanical and hydrogeological properties of a potential host rock for the deep storage of radioactive waste in France

Mari, Jean-Luc; Yven, Béatrice
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/07/2014
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In the context of a deep geological repository of high-level radioactive wastes, the French National Radioactive Waste Management Agency (Andra) has conducted an extensive characterization of the Callovo-Oxfordian argillaceous rock and surrounding formations in the Eastern Paris Basin. As part of this project, an accurate 3D seismic derived geological model is needed. The paper shows the procedure used for building the 3D seismic constrained geological model in depth by combining time-to-depth conversion of seismic horizons, consistent seismic velocity model and elastic impedance in time. It also shows how the 3D model is used for mechanical and hydrogeological studies. The 3D seismic field data example illustrates the potential of the proposed depth conversion procedure for estimating density and velocity distributions, which are consistent with the depth conversion of seismic horizons using the Bayesian Kriging method. The geological model shows good agreement with well log data obtained from a reference well, located closest to the 3D seismic survey area. Modeling of the mechanical parameters such as shear modulus, Young modulus, bulk modulus indicates low variability of parameters confirming the homogeneity of the target formation (Callovo-Oxfordian claystone). 3D modeling of a permeability index (Ik-Seis) computed from seismic attributes (instantaneous frequency...

On the thermal impact on the excavation damaged zone around deep radioactive waste disposal

Delage, Pierre
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 18/11/2014
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Clays and claystones are considered in some countries (including Belgium, France and Switzerland) as a potential host rock for high activity long lived radioactive waste disposal at great depth. One of the aspects to deal with in performance assessment is related to the effects on the host rock of the temperature elevation due to the placement of exothermic wastes. The potential effects of the thermal impact on the excavated damaged zone in the close field are another important issue that was the goal of the TIMODAZ European research project. In this paper, some principles of waste disposal in clayey host rocks at great depth are first presented and a series of experimental investigations carried out on specific equipment specially developed to face the problem are presented. Both drained and undrained tests have been developed to investigate the drained thermal volume changes of clays and claystone and the thermal pressurization occurring around the galleries. This importance of proper initial saturation (under in-situ stresses) and of satisfactory drainage conditions (in spite of the significantly low permeability of claystones) is emphasized, leading to the development of a new hollow cylinder apparatus. It is observed that claystones cannot be considered as overconsolidated clays given that they can exhibit...

Observacion de deshidrataciones y contracciones de una arcilla por difracción de rayos x y microscopia electrónica a temperatura y humedad controladas; Observation of dehydration and retrenchment effects in a claystone by x ray diffraction and electron microscopy under control of temperature and relative humidity

García-Guinea, Javier; Pitalua, F.; Correcher, Virgilio; López-Arce, Paula
Fonte: Sociedad Española de Cerámica y Vidrio Publicador: Sociedad Española de Cerámica y Vidrio
Tipo: Artículo Formato: 331668 bytes; application/pdf
SPA
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[ES] Se aplica una nueva puerta termo-refrigerada de construcción propia, con varios tipos de sensores acoplados (Análisis Térmico Diferencial, Humedad Relativa, Radioluminiscencia), a un difractómetro clásico para registrar perfiles de difracción secuenciales isotermales y noisotermales (en el rango de 17ºC-200ºC). Con este dispositivo se estudiarán procesos de deshidratación y contracción de una arcilla histórica de Toledo. Además, se ha utilizado un microscopio electrónico ambiental (ESEM) con una cámara térmica interna (de 17ºC a 1000ºC) para secar la arcilla y analizarla con el EDS hasta 400ºC. En ambos equipos se controló la temperatura y la humedad relativa dentro de las cámaras de análisis. Los movimientos de contracción de secado han reorientado planos (00l) de la illita, la muestra ha deshidratado hacia los 80ºC y ha deshidroxilado hacia los 280ºC. A elevadas temperaturas in situ (900ºC), se tomaron fotografías de óptica electrónica del óxido de calcio procedente de la descomposición de la calcita.; [EN] A new designed stainless steel door, which holds cooling fluids, permits connect a set of sensors (DTA, RH, RL) to a traditional diffractometer and record sets of isothermal and non-isothermal diffraction profiles (in a range of 17ºC-200ºC) allowing dehydration and retrenchment effects of an historical claystone from Toledo to be studied. In addition...

Effects of sand addition on production of lightweight aggregates from Tunisian smectite-rich clayey rocks

Fakhfakh, E.; Hajjajia, W.; Medhioubb, M.; Rocha, F.; López-Galindo, A.; Setti, M.; Kooli, F.; Zargouni, F.; Jamoussi, F.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 13824 bytes; application/vnd.ms-excel
ENG
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10 pages, 7 figures, 3 tables.; Smectite-rich claystone–marlstone samples from 12 outcrops located in the Southern Atlas domain of Tunisia were investigated with regard to manufacture of lightweight aggregates (LWAs). The clayey materials mainly consist of smectite, kaolinite and illite, together with quartz, calcite, dolomite and feldspars as accessory components. 10–12 mm pellets were prepared from wet paste and initially heated to 600 °C, 700 °C or 800 °C (depending on the raw material) for at least 2 h in order to avoid any explosion of the aggregate. The pellets were then subjected to a quick firing process at 1180 °C. The addition of 15% of quartz sand (< 250 μm grain size) to the raw materials was found to improve some required pre-treatments and give better expansion properties to some of the aggregates. The addition of 1% used automobile oil to the clay and quartz sand mixtures caused the formation of more gas and a drop in bloating temperature. The obtained LWAs were characterized by physical properties such as apparent density, mechanical resistance, water absorption and expansion. The laboratory results were comparable to those of two commercial LWAs from France (Argidécor®) and Portugal (LECA®) and provide new openings for the utilization of Tunisian claystone in civil engineering work or in agricultural applications.; Peer reviewed