Geotechnical Properties of Cemented Volcanic Soil
Publication: Journal of Geotechnical Engineering
Volume 114, Issue 10
Abstract
A volcaniclastic formation, known as Cangahua, found in the Andes of Ecuador and Colombia is focused on. The deposit is composed of moderately cemented fine sand and silt‐sized particles. A pronounced linear correlation is shown between strengh, in terms of both uniaxial compressive and Brazil tensile strengths, and the dry unit weight of the deposit. The tensile strength is unusually high for soil, being between 18 and 29% of the uniaxial compressive strength. Brazil tensile, uniaxial compressive, and triaxial strength characteristics depend on the initial void ratio and degree of saturation. As the saturation declines from 90 to 40%, test results show a fourfold increase in tensile strength. Moreover, increasing degrees of saturation cause a shift from brittle to ductile failure. Slope failures in Cangahua develop from fractures which initiate at zones of high tensile stress. Material properties such as tensile strength and fracture toughness play an important role in explaining and evaluating slope failures in this material. The strong dependence of tensile strength on the degree of saturation indicates that local moisture conditions and exposure to rainfall should be considered in stability assessments.
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References
1.
ASTM. (1987). “Soil and rock; building stones.” Ann. Book of ASTM Standards, Vol. 04.08, Philadelphia, Penn.
2.
Brown, E. T., ed. (1981). Rock characterization testing and monitoring: ISRM suggested methods. Pergamon Press, Oxford, U.K.
3.
Clapperton, C. M., and MacEwan, C. (1985). “Late quaternary moraines in Chimborazo Area, Ecuador.” Artic and Alpine Res., 17(2), 135–142.
4.
Clough, G. W., Sitar, N., and Bachus, R. C. (1981). “Cemented sands under static loading.” J. Geotech. Engrg., ASCE, 107(GT6), 799–817.
5.
Crespo, E. (1987). “Slope stability of the Cangahua Formation, a volcaniclastic deposit from the Interandean Depression of Ecuador.” Thesis presented to Cornell University, at Ithaca, N.Y., in partial fulfillment of the requirements for the degree of Master of Science.
6.
Crespo, E., and Stewart, H. E. (1987). “Stability of cut slopes in Ecuadorian volcaniclastic deposits.” Proc., 8th Panamer. Congress on Soil Mechanics and Foundation Engineering, Cartagena, Colombia, Vol. 3, Aug., 39–50.
7.
Direccion General de Geologia y Minas. (1982). Geologic map of ecuador, 1:1000,000 scale. Instituto Geografico Militar, Quito, Ecuador.
8.
Fisher, R. V. (1961). “Proposed classification of volcaniclastic sediments and rocks.” Geological Soc. of Amer., Bull. 72, 1409–1414.
9.
Fisher, R. V., and Schmincke, H. U. (1984). Pyroclastic rocks. Springer‐Verlag, New York, N.Y.
10.
Hoek, E. (1983). “Strength of jointed rock masses.” Geothecnique, 33(3), 187–223.
11.
Hoshino, K. (1981). “Consolidation and strength of soft sedimentary rocks.” Proc. Int. Symp. on Weak Rock, K. Akai, M. Hayashi, Y. Nishimatsu, eds., Vol. 1, Tokyo, Japan, Sept., 155–160.
12.
Ingraffea, A. R., Gunsallus, K. L., Beech, J. B., and Nelson, P. P. (1984). “A short‐rod based system for fracture toughness testing of rock.” ASTM Symp. on Chevron‐Notched Specimens: Testing and Stress Analysis, ASTM Special Technical Testing Publication 855, J. H. Underwood, S. W. Freiman, and F. I., Baratta, eds., Amer. Soc. for Testing and Materials, Philadelphia, Penn., 152–166.
13.
Jaeger, J. C., and Cook, N. G. W. (1979). Fundamentals of rock mechanics, 3rd Ed., Chapman and Hall, New York, N.Y.
14.
Saada, A. S., Chudnovsky, A., and Kennedy, M. R. (1985). “A fracture mechanics study of stiff clays.” Proc., 11th Int. Conf. Soil Mechanics and Foundation Engineering, San Francisco, Calif., 2, 637–640.
15.
Sauer, W. (1950). “Contribuciones para el Conocimiento del Cuaternario en el Ecuador.” Anales de la Universidad Central del Ecuador, LXXVII(328), 326–364.
16.
Sitar, N. (1983). “Slope stability in coarse sediments.” Special Publication on Geological Environment and Soil Properties, R. Yong, ed., ASCE, New York, N.Y., 82–98.
17.
Terzaghi, K., and Peck, R. B. (1967). Soil mechanics in engineering practice, 2nd Ed., John Wiley and Sons, Inc., New York, N.Y.
18.
Wong, K. S., and Duncan, J. M. (1974). “Hyperbolic stress‐strain parameters for nonlinear finite element analysis of stresses and movements in soil masses.” Geotech. Engrg. Rep., Dept. of Civ. Engrg., Univ. of California, Berkeley, Calif., July, 90 pp.
19.
Yamanouchi, T., Taneda, S., and Kimura, T. (1970). “Damage features in 1968 Ebino earthquakes from the viewpoint of soils engineering.” Soils and Foundations, X(2), 129–144.
20.
Yoshinaka, R., and Yamabe, T. (1981). “Deformation behavior of soft rocks.” Proc. Int. Symp. on Weak Rock, K. Akai, M. Hayashi, V. Nishimatsu, eds., Vol. 1, Tokyo, Japan, 87–92.
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Copyright © 1988 ASCE.
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Published online: Oct 1, 1988
Published in print: Oct 1988
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