8 research outputs found

    Hydraulique des turbines de forage, essais en laboratoire, performances d’exploitation

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    Hydraulic considerations on turbodrills, laboratory tests and industrial performances. I. — Hydraulic considerations on turbodrills. 1.1. — Jonval turbine — Introduction to turbodrills — Idea of multiple stages — Rotors and stators — The turbodrill described. 1.2. — Influence of fluid medium — Drilling muds — Wear problems affecting the hydraulic circuits. II. — Laboratory tests. II. 1. — Hydraulic tests. II. 2. — Wear tests. II. 3. — Test rig for complete turbodrills. III. — Industrial turbodrill management, performance and operating parameters.I. — Hydraulique des turbines de forage. I.1. — Turbine Jonval. — Introduction Ă  la turbine de forage. — Notion d'Ă©tages multiples. — Roues et distributeurs. — Description de la turbine. I.2. — Influence de la nature du fluide utilisĂ©. — Boues de forage. — ProblĂšmes d'usure concernant les circuits hydrauliques. II. — Essais en laboratoire. II.1. — Essais hydrauliques. II.2. — Essais d'usure. II.3. — Banc d'essai pour turbines complĂštes. III. — Exploitation des turbines de forage : performances et paramĂštres d'utilisation.Dagallier B., Lagacherie G. Hydraulique des turbines de forage, essais en laboratoire, performances d’exploitation. In: Turbines et pompes hydrauliques. Compte rendu des cinquiĂšmes journĂ©es de l'hydraulique, Aix-en-Provence, 26, 27 et 28 juin 1958. Tome 2, 1959

    Altération du minerai de fer dans les mines abandonnées de Lorraine

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    Une Ă©tude de l’évolution minĂ©ralogique du minerai de fer de Lorraine formant les piliers abandonnĂ©s des anciens travaux a Ă©tĂ© rĂ©alisĂ©e pour mieux comprendre le mĂ©canisme des effondrements miniers. Des Ă©chantillons ont Ă©tĂ© prĂ©levĂ©s dans une zone sans travaux miniers, au cƓur de certains piliers et au bord de piliers dont la date d’exposition Ă  l’atmosphĂšre miniĂšre est connue. Les Ă©chantillons ont Ă©tĂ© analysĂ©s au MEB, Ă  la microsonde et au diffractomĂštre Ă  rayons X. Il en rĂ©sulte que la minĂ©ralogie et la microstructure du minerai de fer exploitĂ© Ă©voluent avec le temps. Cette Ă©volution, d’origine anthropique, diffĂšre de l’évolution diagĂ©nĂ©tique. Elle correspond Ă  une premiĂšre phase d’altĂ©ration du ciment inter-oolitique (carbonates de fer et phyllosilicates ferrifĂšres) suivie par une seconde phase de nĂ©oformation de phyllosilicates ferrifĂšres puis d’un dĂ©pĂŽt d’oxydes de fer. Une Ă©tude de microbiologie a montrĂ© l’influence des bactĂ©ries sur ces phĂ©nomĂšnes. L’influence des conditions physico-chimiques environnantes a Ă©galement Ă©tĂ© discutĂ©e. Ces modifications microscopiques se traduisent Ă  l’échelle macroscopique par une diminution de la cohĂ©sion et donc de la rĂ©sistance de la roche, et influent donc sur la stabilitĂ© Ă  long terme des piliers abandonnĂ©s

    Delineating shallow Neogene deformation structures in northeastern ParĂĄ State using Ground Penetrating Radar

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    The geological characterization of shallow subsurface Neogene deposits in northeastern ParĂĄ State using Ground Penetrating Radar (GPR) revealed normal and reverse faults, as well as folds, not yet well documented by field studies. The faults are identified mostly by steeply-dipping reflections that sharply cut the nearby reflections causing bed offsets, drags and rollovers. The folds are recognized by reflections that are highly undulating, configuring broad concave and convex-up features that are up to 50 m wide and 80 to 90 ns deep. These deformation structures are mostly developed within deposits of Miocene age, though some of the faults might continue into younger deposits as well. Although the studied GPR sections show several diffractions caused by trees, differential degrees of moisture, and underground artifacts, the structures recorded here can not be explained by any of these ''noises''. The detailed analysis of the GPR sections reveals that they are attributed to bed distortion caused by brittle deformation and folding. The record of faults and folds are not widespread in the Neogene deposits of the Bragantina area. These GPR data are in agreement with structural models, which have proposed a complex evolution including strike-slip motion for this area from the Miocene to present.<br>A caracterização geolĂłgica de depĂłsitos neĂłgenos ocorrentes em sub-superfĂ­cie rasa no nordeste do Estado do ParĂĄ, usando Radar de Penetração no Solo (GPR), revelou a presença de falhas normais e reversas, bem como dobras, ainda nĂŁo documentadas em estudos de campo prĂ©vios. As falhas sĂŁo identificadas por reflexĂ”es inclinadas que cortam bruscamente reflexĂ”es vizinhas, causando freqĂŒentes deslocamentos de camadas. As dobras sĂŁo reconhecidas por reflexĂ”es fortemente ondulantes, configurando feiçÔes cĂŽncavas e convexas que medem atĂ© 50 m de amplitude e 80 a 90 m de profundidade. Estas estruturas deformacionais desenvolvem-se, principalmente, em depĂłsitos de idade miocĂȘnica, embora algumas falhas possam estender-se, tambĂ©m, a depĂłsitos mais jovens. Embora as seçÔes de GPR estudadas mostrem vĂĄrias difraçÔes causadas por ĂĄrvores, umidade do solo, e objetos enterrados, as estruturas registradas aqui nĂŁo podem ser explicadas por nenhum destes ''ruĂ­dos''. A anĂĄlise detalhada das seçÔes de GPR revelou que as feiçÔes deformacionais estudadas estĂŁo relacionadas com distorçÔes de camadas causadas por deformaçÔes rĂșptil e dĂșctil. Embora falhas e dobras nĂŁo sejam amplamente registradas em depĂłsitos neĂłgenos da Zona Bragantina, os dados aqui apresentados sĂŁo consistentes com modelos estruturais, que propĂ”em uma evolução complexa incluindo movimentaçÔes transcorrentes para esta ĂĄrea, do Mioceno atĂ© o presente
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