Undrained Multidirectional Direct Simple Shear Behavior of Cohesive Soil
Publication: Journal of Geotechnical Engineering
Volume 122, Issue 2
Abstract
The foundation soil of an offshore Arctic gravity structure is subjected to complex loading conditions. In addition to radial shear stresses induced by the weight of a structure, large horizontal shear forces from ice loads can produce large rotations and even reversal in the direction of horizontal shear stresses acting on soil elements within the foundation soil. The Multidirectional Direct Simple Shear (MDSS) apparatus was developed to simulate, at the element level, these states of stress. The MDSS first consolidates a circular specimen under both a vertical stress (σ′vc) and a horizontal shear stress (τhc=τ1; setdown conditions). The specimen is then sheared undrained by applying a second independent horizontal shear stress (τ2; ice loading) at an angle θ relative to the horizontal shear stress τ1. The experimental program of MDSS and Geonor Direct Simple Shear tests on normally consolidated Boston Blue Clay used τhc=τ1= 0.2σ′vc and varied θ in 30° increments from zero (shear in the same direction) to 180° (shear in the opposite direction). The peak undrained resistance decreased almost twofold from θ= 0° to θ= 120°, and the deformation behavior varied from very brittle at low θ angles to becoming ductile at higher angles. These dramatic changes in foundation response are an important design issue.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Baligh, M. M., and Azzouz, A. S. (1985). “Stability analysis for gravity structures.”Tech. Progress Rep. No. 4, Center for Sci. Excellence in Offshore Engrg., Dept. of Civ. Engrg., Massachusetts Inst. of Technol., Cambridge, Mass.
2.
Bjerrum, L., and Landva, A.(1966). “Direct simple shear tests on Norwegian quick clay.”Géotechnique, London, England, 16(1), 1–20.
3.
DeGroot, D. J., Germaine, J. T., and Gedney, R.(1991). “An automated electropneumatic control system for direct simple shear testing.”Geotech. Testing J., 14(4), 339–348.
4.
DeGroot, D. J., Ladd, C. C., and Germaine, J. T. (1992). “Direct simple shear testing of cohesive soils.”Res. Rep. No. R92-18, Center for Sci. Excellence in Offshore Engrg., Dept. of Civ. Engrg., Massachusetts Inst. of Technol., Cambridge, MA.
5.
DeGroot, D. J., Germaine, J. T., and Ladd, C. C.(1993). “The multidirectional direct simple shear apparatus.”Geotech. Testing J., ASTM, 16(3), 283–295.
6.
DeGroot, D. J., Germaine, J. T., and Ladd, C. C.(1994). “Influence of nonuniform stresses on measured DSS shear-strain behavior.”J. Geotech. Engrg., ASCE, 120(5), 892–912.
7.
Ladd, C. C. (1991). “Stability evaluation during staged construction: the 22nd Karl Terzaghi lecture.”J. Geotech. Engrg., ASCE, 117(4), 540–615.
8.
Ladd, C. C., and Edgers, L. (1972). “Consolidated-undrained direct simple shear tests on saturated clay.”Res. Rep. R72-82, Dept. of Civ. Engrg., Massachusetts Inst. of Technol., Cambridge, Mass.
9.
Ladd, C. C., Weaver, J. S., Germaine, J. T., and Sauls, D. P. (1985). “Strength-deformation properties of arctic silt.”Proc., Arctic '85, ASCE, New York, N.Y., 820–829.
10.
Whittle, A. J., DeGroot, D. J., Ladd, C. C., and Seah, T. H.(1994). “Model prediction of anisotropic behavior of boston blue clay.”J. Geotech. Engrg., ASCE, 120(1), 199–224.
Information & Authors
Information
Published In
Journal of Geotechnical Engineering
Volume 122 • Issue 2 • February 1996
Pages: 91 - 98
Copyright
Copyright © 1996 American Society of Civil Engineers.
History
Published online: Feb 1, 1996
Published in print: Feb 1996
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.