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Optical and Electron Microscopic Investigation of Shear Induced Structures in Lightly Consolidated (Soft) and Heavily Consolidated (Hard) Kaolinite

Published online by Cambridge University Press:  01 July 2024

R. H. Foster  and
P. K. De
R. H. Foster
Affiliation:
The City University, London, England
P. K. De
Affiliation:
The City University, London, England
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Abstract

A review of fabric studies of clays suggests the need for relating those fabric characteristics which are revealed at the two levels of magnification provided by optical and electron microscopy, and a technique to achieve this has been developed and is described within the context of the initial stages of a long term study of the interrelation between fabric and engineering behaviour. Two kaolinitic clays with contrived fabrics were prepared by controlling particle size, moisture content and pH of suspension, and consolidation load and were subjected to shear loading to failure. Resin impregnation techniques which permit the kaolinite to be cut into thin sections for transmission electron microscopy have been optimized with the object of minimizing fabric strain and damage during ultratomy.

The fabrics of the hard and soft ambient material are qualitatively compared by means of electron micrographs and are explained in terms of the preparatory procedures adopted for fabric control. The fabrics of the two types of shear induced structures are also qualitatively compared and explained in terms of the original fabrics and the subsequent shear loading.

Résumé

Résumé

Une revue des études de structure des argiles suggère la nécessité de rapporter ces caractéristiques qui sont révélées à deux niveaux de grossissement fournis par la microscopie optique et électronique, et une technique, spécialement élaborée pour cette étude, est décrite dans le contexte des premiers stades d’une étude à long terme sur la relation entre la structure et son comportement du point de vue engineering. Deux argiles kaolinitiques, avec structures aménagées, ont été préparées en contrôlant la grosseur des particules, la teneur d’humidité et la pourcentage de la suspension, ainsi que la charge de consolidation, et ces argiles ont été ensuite soumises jusqu’au bout à une force de cisaillement. Les techniques d’imprégnation de résine qui permettent de découper la kaolinite en sections minces, pour la microscopie électronique, ont été optimisées en vue de réduire au minimum la contrainte et l’endommagement de la texture pendant l’ultratomie.

Les structures des matériaux ambiants dures et souples sont comparées qualitativement au moyen de micrographes électroniques et sont expliquées en terme de procédés préparatoires adoptés pour le contrôle de la structure. Les textures des deux types de structure à cisaillement induit sont également comparées, du point de vue qualitatif, et une explication est donnée en terme des textures originelles et de la force de cisaillement ultérieure.

Kurzreferat

Kurzreferat

Eine Übersicht über Untersuchungen der Textur von Tonmineralen lässt es geboten erscheinen diejenigen Texturmerkmale, die auf zwei Vergrösserungsebenen durch optische und durch Elektronenmikroskopie sichtbar gemacht werden, in eine Beziehung zu einander zu bringen, und es ist zu diesem Zwecke eine Methode entwickelt worden, die im Zusammenhang mit den Anfangsphasen einer langzeitigen Untersuchung der Beziehungen zwischen Textur und technischem Verhalten, beschrieben wird. Zwei kaolinitische Tone mit geplanter Textur wurden bereitet durch Kontrolle der Teilchengrösse. des Feuchtigkeitsgehaltes und des pH der Suspension sowie der Verdichtungslast, und wurden einer Scherbeanspruchung bis zum Bruch unterzogen. Verfahren der Kunstharzimprägnierung, die es gestatten den Kaolinit in dünne Schnitte für die Transmissionselektronenmikroskopie zu schneiden, wurden optimisiert um die Beanspruchung der Textur und die Beschädigung während der Ultratomie auf ein Minimum zu beschränken.

Die Texturen des harten und weichen Umgebungsmaterials werden qualitativ mittels Elektronen-mikrographien verglichen und werden mit den für die Kontrolle der Textur angewendeten Verfahren in Beziehung gebracht. Die Texturen der zwei Arten durch Scherung hervorgerufener Gefüge werden ebenfalls qualitativ verglichen und im Zusammenhang mit der ursprünglichen Texturen und der nachfolgenden Scherbelastung erörtert.

Резюме

Резюме

Обзор текстурных исследований глин выявил необходимость сопоставления тех их характеристик, которые получаются на двух уровнях увеличения, т. е. с помощью оптической и электронной микроскопии. Для решения этой задачи разработана методика, которая изложена ранее вместе с результатами длительного предварительного исследования соотношений между структурно-морфологическими и техническими характеристиками глин. Две каолинитовые глины с заданными текстурами приготавливались с контролем размеров частиц, влажности, рН суспензии и степени спрессованности, и подвергались сдвиговым напряжениям с целью образования нарушений. Методика пропитывания пластическими наполнителями, позволяющая получить тонкие срезы каолинита для исследования в электронном микроскопе, была несколько усовершенствована для уменьшения структурных напряжений и повреждений при ультрамикротомировании.

Строение твердых и мягких материалов качественно сравнивалось по электронномикро-скопическим снимкам и трактовалось с учетом методик препарирования, применяемых при структурно-морфологических исследованиях. Особенности сдвиговых структур двух типов также количественно сравнивались и объяснялись на основе данных о строении исходных материалов и степени последующей сдвиговой обработки.

Type
Research Article
Information
Clays and Clay Minerals , Volume 19 , Issue 1 , March 1971 , pp. 31 - 47
Copyright
Copyright © 1971, The Clay Minerals Society

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References

Bishop, A. W. (1966) Sixth Rankine Lecture: The strength of soils as engineering Materials: Geotechnique 16, 89–128.CrossRefGoogle Scholar
Bjerrum, L. (1967) Engineering Geology of Normally Consolidated Marine Clays as related to the settlements of buildings: Geotechnique 17. 83–118.Google Scholar
Bjerrum, L. (1969) Discussion on speciality session 7. Proc. Intern. Conf. on Soil Mech. Found. E, 7th, Mexico. Vol 3, p. 464.Google Scholar
Bjerrum, L. and Kenney, T. C. (1967) Effect of Structure on the Shear behaviour of Normally Consolidated Quick Clays: Proc. Geotechnical Conf. Oslo Vol 2, 19–27.Google Scholar
Bjerrum, L., Løken, T., Heiberg, S. and Foster, R. (1969) A fluid study of factors responsible for quick clay slides: Proc. Intern. Conf. Soil Mech. Found E, 7th, Mexico Vol. 2, p. 531–540.Google Scholar
De, P. K. (1970) Kaolin-microstructure after consolidation and direct shear: Ph.D. Thesis, the City University, London.Google Scholar
Foster, R. H. (1967) Discussion on Shear Strength Properties of Natural Soils and Rocks: Proc. Geo- technical Conf, Oslo Vol. 2, p. 174.Google Scholar
Grim, R. E. (1953) Clay Mineralogy. McGraw Hill, New York.CrossRefGoogle Scholar
Kay, D. (1965) Techniques for Electron Microscopy. Blackwell, Scientific Publications Oxford.Google Scholar
Kenney, T. C., Moum, J. and Berre, T. (1967) An experimental study of bonds in a natural clay: Proc. Geotechnical Conf. Oslo Vol. 1, 65–69.Google Scholar
Lambe, T. W. (1953) The structure of inorganic soil: Proc. Am. Soc. Civil Engng 79, paper No. 315.Google Scholar
Lambe, T. W. (1958a) The structure of compacted clay: J. Soil Mech. Fdns. Div. Am. Soc. Civ. Engrs. 84, SM2, paper No. 1655.Google Scholar
Lambe, T. W. (1958b) The engineering behaviour of compacted clay: J. Soil Mech. Fdns. Div. Am. Soc. Civ. Engrs. 84, SM2.Google Scholar
Martin, R. T. (1965) Quantitative fabric of consolidated Kaolinite: Research report R65-47, M.I.T.Google Scholar
Martin, R. T. (1966) Quantitative fabric of wet kaolinite: Clays and Clay Minerals 14, 271–287.CrossRefGoogle Scholar
Meade, R. H. (1964) Removal of water and rearrangement of particles during the compaction of clayey sediments —review: U.S., Geol. Surv., Prof. Pap. 497-B, 23.Google Scholar
Mitchell, J. K. (1956) The fabric of natural clays and its relation to engineering properties: Highw. Res. Bd., Proc. 35, 693–713.Google Scholar
Morgenstern, N. R. (1969) Structural and physico-chemical effects on the properties of clays: Proc. Intern. Conf. Soil Mech. Found. E., 7th Mexico Vol. 3, pp. 455–471.Google Scholar
Morgenstern, N. R. and Tchalenko, J. S. (1967a) The optical determination of preferred orientation in clays and its application to the study of microstructure in consolidated Kaolin, I and II: Proc. Royal Soc. 300A. 218–250.Google Scholar
Morgenstern, N. R. and Tchalenko, J. S. (1967b) Microscopic structures in Kaolin subjected to direct shear: Geotechnique 17, 309–328.CrossRefGoogle Scholar
Moum, J. Sopp, O. I. and Løken, T. (1968). Stabilization of undisturbed quick clay by salt wells: Vag-Ock vatten bygarren 14 No. 8, 23-29; Also published in Norwegian Geotechnical Institute Publ., 81.Google Scholar
Pusch, R. (1967) A technique for investigation of clay microstructure: J. Microsc. Paris. 6, 963–986.Google Scholar
Quigley, R. M. and Thompson, C. D. (1966) The fabric of anisotropically consolidated sensitive marine clay: Can. Geotech. J. 3, 61–73.CrossRefGoogle Scholar
Ramsey, J. G. (1967) Folding and fracturing of rocks: McGraw-Hill, London.Google Scholar
Roscoe, K. H. (1967) Discussion. Proc. Geotechnical Conf. Oslo Vol. 2, p. 167.Google Scholar
Rosenqvist, I. Th.. (1955) Investigations in the clay- electrolyte water system: Norw. Geo. Inst. 9, 125.Google Scholar
Rosenqvist, I. Th.. (1959) Physico-chemical properties of soils: soil water systems! J. Soil Mech. Fdns. Div. Am. Soc. Civ. Engrs. 85, SM2.Google Scholar
Rosenqvist, I. Th.. (1962) The influence of physico-chemical factors upon the mechanical properties of clays: Clays and Clay Minerals, 9, 12–27.CrossRefGoogle Scholar
Rosenqvist, I. Th.. (1968) Mechanical Properties of Soils from a Mineralogical-physical-chemical view point: Communication from Institutt for Geologi, Universitetet, Oslo .Google Scholar
Scott, R. F. (1963) Principles of Soil Mechanics. Addison- Wesley. London.Google Scholar
Skempton, A. W. (1960) Effective stresses in soils rocks and concrete; Proc. Conf. Pore Pressure und suction in soils Vol. 4, p. 16, London.Google Scholar
Skempton, A. W. (1964) Long term stability of clay slopes: Geotechnique 14, 77–101.CrossRefGoogle Scholar
Sloane, R. L. and Keie, T. R. (1966) The fabric of mechanically compacted Kaolin: Clays and Clay Minerals. 14, 289–296.CrossRefGoogle Scholar
Smart, P. (1967) Particle arrangements in Kaolin: Clays and Clay Minerals 15, 241–254.CrossRefGoogle Scholar
Tchalenko, J. S. (1967) Influence of shear and consolidation on the microscopic structures of some clays: Ph.D. thesis University of London.Google Scholar
Tovey, N. K. (1970) Electron-Microscopy of Clays: Ph.D. Thesis, Cambridge University.Google Scholar
Ward, W. (1967) Panel Discussion. Proc. Geotechnical Conf. Oslo Vol. 2. p. 139.Google Scholar
Weast, R. C. (1968/69) Handbook of Chemistry and Physics: Chemical Rubber Pub. Co., Cleveland, Ohio.Google Scholar
Wu, T. H. (1966) Soil Mechanics: Allyn & Bacon, Boston .Google Scholar