INFLUENCE OF THE MICROSTRUCTURE AND MINERALOGICAL COMPOSITION ON THE LABORATORY HYDRAULIC CONDUCTIVITY OF MARLS FROM NORTHERN PELOPONNESE


T. Χριστοδουλοπούλου
Π. Τσώλη-Καταγά
Abstract

The role which microstructural characteristics and clay mineralogy plays on the saturated hydraulic conductivity value (k) of marls from Northern Péloponnèse, measured in the laboratory, is studied. This value must be taken under consideration when severe geotechnical problems are investigated (e.g. embankment foundations, landslides phenomena involving clayey sediments, soil conditioning e.t.c.) or empirical functions are applied to predict hydraulic conductivity from basic geotechnical properties. The marly samples were analysed by x-ray diffraction (XRD) and by thermo-gravimetric methods (DTA, TG) for the determination of mineralogical composition of clay fraction and by scanning electron microscopy (SEM) for the study of their microstructure. Their basic physical characteristics (grain-size distribution, e, WL, WP, IP, GS, Yd, n) were also determined. The coefficient of permeability (or hydraulic conductivity, k) was measured by the falling head method and the values obtained range between 1.66 10~8 and 1.06 10"6 cm/s, with a few exceptions. Our results indicate that the occurrence of swelling clay minerals in these cohesive marly sediments influences the value of hydraulic conductivity. Because of the double-layer effect not all the pore space contributes to seepage. Furthermore, the aggregation or flocculation of clay minerals and other microstructural characteristics related to the packing of structural constituents (forming an open or tight microstructure), the shape and the distribution of micropores, and the cementation degree of the microstructure are influence factors that affect the value of k. Predicting k, using empirical functions reported by several researchers for cohesive materials, or from simple correlations, as this of k versus clay fraction which is reported in this paper, is not absolutely safe, especially for cemented sediments as marls. Physicochemical factors, as the above-mentioned, play a prevalent role on the hydraulic conductivity value and they cannot be quantified and accounted in existing models.

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  • Engineering Geology, Hydrogeology, Urban Geology
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References
Al-Tabbaa Α. & Wood D.M. 1987. Some measurements of the permeability of kaolin. Geotechnique, 37(4), 499- 503.
Anagnostopoulos AG., Kalteziotis N., Tsiambaos G.K. & Kavvadas M. 1991. Geotechnical properties of the Corinth Canal marls. Geotech. & Geol. Engn., 9, 1-26.
Aubertin M., Bussiére Β. & Chapuis R.P. 1996. Hydraulic conductivity of homogenized tailings from hard rock mines. Canadian Geotechnical Journal, 33{3), 470-482.
Bell F.G., Cripps J.C. & Culshaw M.G. 1986. A review of the engineering behaviour of soils and rocks with respect to groundwater. Groundwater in Engineering Geology, Geological Society of London, Eng. Geol. Special Pubi., 3, 1-23.
Carman P.C. 1956. Flow of Gases Through Porous Media. Academic Press, Inc., New York, 182pp.
Chapuis R.P. & Aubertin M. 2003. On the use of the Kozeny-Carman equation to predict the hydraulic conductivity of soils. Can. Geotech. J., 40, 616-628.
Chapuis R.P. & Gill D.E. 1989. Hydraulic anisotropy of homogeneous soils and rocks: Influence of the densification process. Bull. Int. Ass. Engn. Geol, 39, 75-86.
Chin D.A. 2000. Water-Resources Engineering. Prentice Hall, Upper Saddle River, N.J, 750pp.
Daoud Y. & Robert M. 1992. Influence of particle size and clay organization on hydraulic conductivity and moisture retention of clays from saline soils. App. Clay Sci., 6, 293-299.
Das M.B. 1990. Principles of Geotechnical Engineering. PWS-KENT Pubi. Comp., Boston, 2nd Ed., 665pp.
Frenkel H., Levy G.J. & Fey M.V. 1992. Clay dispersion and hydraulic conductivity of clay-sand mixtures as affected by the addition of various anions. Clays and Clay Minerals, 40(5), 515-521.
Gillott E.J. 1987. Clay in Engineering Geology. Elsevier, Amsterdam, 449pp.
Hazen A. 1911. Discussion of dams on sand foundations. Transactions, American Society of Civil Engineers, 73, 199-203.
Johnston I.W. & Novello E.A. 1993. Soft rocks in the geotechnical spectrum. Proc. of Int. Symp. in Geotech. Engn. of Hard Soils - Soft Rocks, Anagnostopoulos et al. (Eds), Balkema, Rotterdam, 1, 177-184.
Kozeny J. 1953. Hydraulik. Ihre Grundlagen und Praktische Anwendung, Wien, Springer, 588pp.
Lambe T.W. 1951. Soil Testing for Engineers. John Wiley & Sons, New York, 165pp.
Mbonimpa M., Aubertin M., Chapuis R.P. & Bussiére Β. 2002. Practical pedotransfer functions for estimating the saturated hydraulic conductivity. Geotech. & Geol. Engn., 20, 235-259.
Mesri G. & Olson R.E. 1971. Mechanisms controlling the permeability of clays. Clays and Clay Minerals, 19, 151-158.
Nagaraj T.S., Pandian N.S. & Narasimha Raju P.S.R. 1993. Stress state-permeability relationships for finegrained soils. Technical Note. Geotechnique, 43(2), 333-336.
Osipov V.l. 1975. Structural bonds and the properties of clays. Bull. Int. Ass. Engn. Geol., 12, 13-20.
Puckett W.E., Dane J.H. & Hajek B.F. 1985. Physical and mineralogical data to determine soil hydraulic properties. Soil Sci. Soc. Am. J., 49, 831-836.
Schaap M.G. & Leij F.J. 1998. Database-related accuracy and uncertainty of pedotransfer functions. Soil Science, 163(10), 765-779.
Schlueter E.M., Zimmerman R.W., Witherspoon P.A. & Cook N.G.W. 1997. The fractal dimension of pores in sedimentary rocks and its influence on permeability. Engn. Geol., 48, 199-215.
Shepherd R.G. 1989. Correlations of permeability and grain size. Ground Water, 27(5), 633-638.
Taylor D.W. 1948. Fundamentals of Soil Mechanics. John Wiley and Sons, New York, 700pp.
Tieje O. & Hennings V. 1996. Accuracy of the saturated hydraulic conductivity prediction by pedotransfer functions compared to the variability within FAO textural classes. Geoderma, 69, 71-84.
Vukovic M. & Soro A. 1992. Determination of hydraulic conductivity of porous media from grain-size composition. Water Resources Pubi., Littleton, Colorado, 83pp.
Younger P.L. 1992. The hydrogeological use of thin sections: inexpensive estimates of groundwater flow and transport parameters. Q. J. Engn. Geo!., 25, 159-
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