Strain Localization in Extension Tests on Granular Materials
Publication: Journal of Engineering Mechanics
Volume 121, Issue 7
Abstract
An experimental study on granular materials in triaxial extension at confining pressures from 0.25 to 68 MPa is presented. Drained and undrained tests were performed utilizing cylindrical specimens. Strain localization was repeatedly encountered in the form of specimen necking. The strain localization was determined to initiate very early in the test. The cause of the strain localization was determined to be the inherent instability in the axisymmetric extension test, which allows stresses, and therefore deformations, to concentrate at the weakest part of the specimen. This instability is a result of the inward radial strains experienced during the extension test. The effect is to lower the measured failure stresses and strains resulting in the conclusion that the conventional extension test is unreliable for determining soil strength in extension. A method was developed to enforce uniform strains in triaxial extension tests on cylindrical specimens by the use of small metal plates separated by lubricated latex membranes. Using this method a series of uniform-strain tests were performed. Detailed comparisons between strain-localized and uniform-strain tests are presented.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Barden, L., and Proctor, D. C.(1971). “The drained strength of granular material.”Can. Geotech. J., 8(8), 372–383.
2.
Green, G. E., and Bishop, A. W.(1969). “A note on the drained strength of sand under generalized strain conditions.”Geotechnique, 19(1), 144–199.
3.
Ko, H.-Y., and Scott, R. F.(1967). “A new soil testing apparatus.”Geotechnique, 17(1), 40–57.
4.
Lade, P. V. (1972). “The stress-strain and strength characteristics of cohesionless soils,” PhD dissertation, Univ. of California, Berkeley, Calif.
5.
Lade, P. V. (1982). “Localization effects in triaxial tests on sands.”Deformation and Failure of Granular Mat., Symp. on Deformation and Failure of Granular Mat., 461–471. Int. Union on Theoretical and Appl. Mech. (IUTAM), Delft, The Netherlands.
6.
Lade, P. V., and Duncan, J. M. (1973). “Cubical triaxial tests on cohesionless soil.”J. Soil Mech. and Found. Div., ASCE, 99(SM10), 793–812.
7.
Lam, W. K., and Tatsuoka, F. (1988). “Triaxial compressive and extension strength of sand affected by strength anisotropy and sample slenderness.”Adv. Triaxial Testing of Soil and Rock, ASTM STP 977. ASTM, Philadelphia, Pa., 655–666.
8.
Molenkamp, F.(1985). “Comparison of frictional material models with respect to shear band initiation.”Geotechnique, 35(2), 127–143.
9.
Nakai, T., and Matsuoka, H.(1983). “Shear behavior of sand and clay under three-dimensional stress condition.”Soils and Found., 23(2), 26–47.
10.
Peters, J. F., Lade, P. V., and Bro, A. (1988). “Shear band formation in triaxial and plane strain tests.”Adv. Triaxial Testing of Soil and Rock, ASTM STP 977. R. T. Donaghe, R. C. Chaney, and M. L. Silver, eds., ASTM, Philadelphia, Pa., 604–627.
11.
Procter, D. C., and Barden, L.(1969). “Discussion on `A note on the drained strength of sand under generalized strain conditions,' by G. E. Green, and A. W. Bishop.”Geotechnique, 19(3), 424–426.
12.
Reades, D. W., and Green, G. E.(1976). “Independent stress control and triaxial extension tests on sand.”Geotechnique, 26(4), 551–576.
13.
Rice, J. R. (1976). “The localization of plastic deformation.”Proc., 14th Conf. on Theoretical and Appl. Mech., W. T. Koiter, ed., North-Holland Publishing Co., Amsterdam, The Netherlands, 207–229.
14.
Roscoe, K. H., Schofield, A. N., and Thurairajah, A. (1963). “An evaluation of test data for selecting a yield criterion for soils.”Lab. Shear Testing of Soils STP No. 3, ASTM, Philadelphia, Pa.
15.
Rudnicki, J. W., and Rice, J. R. (1975). “Conditions for the localization of deformation in pressure-sensitive dilatant materials.”J. Mech. and Physics of Solids, Vol. 23, 371–394.
16.
Shibata, T., and Karube, D. (1965). “Influence of the variation of the intermediate principal stress on the mechanical properties of normally consolidated clays.”Proc., 6th Int. Conf. on Soil Mech. and Found. Engrg., Vol. 1, Montreal, Canada, 359–363.
17.
Sutherland, H. B., and Mesdary, M. S. (1969). “The influence of the intermediate principal stress on the strength of sand.”Proc., 7th Int. Conf. on Soil Mech. and Found. Engrg., Vol. 1, Mexico City, Mexico, 391–399.
18.
Wu, W., and Kolymbas, D.(1991). “On some issues in triaxial extension tests.”Geotech. Testing J., 14(3), 276–287.
19.
Yamada, Y., and Ishihara, K.(1979). “Anisotropic deformation characteristics of sand under three dimensional stress conditions.”Soils and Found., 19(2), 79–91.
20.
Yamamuro, J. A., and Lade, P. V.(1993). “B-Value measurements for granular materials at high confining pressures.”Geotech. Testing J., 16(2), 165–171.
21.
Yamamuro, J. A. (1993). “Instability and behavior of granular materials at high pressures,” PhD dissertation, Univ. of California, Los Angeles, Calif.
Information & Authors
Information
Published In
Copyright
Copyright © 1995 American Society of Civil Engineers.
History
Published online: Jul 1, 1995
Published in print: Jul 1995
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.