Base Stability of Deep Excavation in Anisotropic Soft Clay
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 124, Issue 9
Abstract
Base stability of a deep excavation in clay is affected not only by soil properties such as soil strength and strength anisotropy, but also by several construction factors, such as the stiffness and depth of the excavation support wall and the depth of excavation. However, not all these influencing factors can be dealt with by the limit equilibrium methods currently used to analyze the base stability of a deep excavation in clay. The method proposed in this paper takes into account the influence of strength anisotropy and nonhomogeneity of soft clay, and the depth of the wall. The method is derived from the upper bound theory of bearing capacity and an assumed failure mechanism and is applied to study the base stability of deep excavations supported with internal braces and a concrete diaphragm wall in soft clay. To describe the strength anisotropy of soft clay, a total stress anisotropic strength criterion is adopted. The suitability of this method for analyzing the base stability of deep excavations is verified by comparison with numerical study results of deep excavations in Boston and a base failure case in Taipei. Limitations of this method, such as the minimum depth of excavation wall required and the lower bound ratio between the depth of the excavation wall and the width of excavation, are discussed also.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Atkinson, J. H. (1980). Foundation and slope: an introduction to applications of critical state soil mechanics. McGraw-Hill (UK), Berkshire, U.K.
2.
Bjerrum, L., and Eide, O.(1956). “Stability of strutted excavations in clay.”Geotechnique, 6(1), 32–47.
3.
Clough, G. W., and Hansen, L. A.(1981). “Clay anisotropy and braced wall behavior.”J. Geotech. Engrg. Div., ASCE, 107(7), 893–913.
4.
Hashash, Y. M. A., and Whittle, A. J.(1996). “Ground movement prediction for deep excavations in soft clay.”J. Geotech. Engrg., ASCE, 122(6), 474–486.
5.
Hong, W. P., and Lade, P. V.(1989). “Elasto-plastic behavior of Ko-consolidated clay in torsion shear tests.”Soils and Found., 29(2), 57–70.
6.
Koutsoftas, D. C., and Ladd, C. C.(1985). “Design strengths for an offshore clay.”J. Geotech. Engrg., ASCE, 111(3), 337–355.
7.
Ladd, C. C.(1991). “Stability evaluation during staged construction.”J. Geotech. Engrg., ASCE, 117(4), 540–615.
8.
Ladd, C. C., Bovee, R. B., Edgers, L., and Rixner, J. J. (1971). “Consolidated-undrained plane strain shear test on Boston blue clay.”Res. Rep. R71-13, No. 273, Dept. of Civ. Engrg., Massachusetts Institute of Technology, Cambridge, Mass.
9.
Ladd, C. C., Foott, R., Ishihara, K., Schlosser, F., and Poulos, H. G. (1977). “Stress-deformation and strength characteristics.”State-of-the-Art Report: Proc., 9th ICSMFE, Vol. 2, Tokyo, Japan, 421–494.
10.
Lumb, P., and Schmertmann, J. H.(1966). “Discussion of `Stability of slopes in anisotropic soils.”' J. Soil Mech. and Found. Div., ASCE, 92(1), 199–203.
11.
Mitachi, T., and Kitago, S.(1980). “Undrained triaxial and plane strain behavior of saturated remolded clay.”Soils and Found., 20(1), 12–28.
12.
O'Neill, D. A. (1985). “Undrained strength anisotropy of an overconsolidated thixotropic clay,” MS thesis, Massachusetts Institute of Technology, Cambridge, Mass.
13.
O'Rourke, T. D. (1992). “Base stability and ground movement prediction for excavations in soft clay.”Proc., ICE Conf. on Retaining Structure, Thomas Telford Ltd., London, U.K., 657–687.
14.
Prevost, J. H.(1979). “Undrained shear tests on clays.”J. Geotech. Engrg. Div., ASCE, 105(1), 49–64.
15.
Prevost, J. H., and Hoeg, K. (1977). “Plasticity model for undrained stress-strain behavior.”Proc., 9th ICSMFE, Vol. 1, Tokyo, Japan, 255–261. Recommendations for design of building foundations . (1974). Architectural Institute of Japan, Tokyo, Japan.
16.
Seah, T. H. (1990). “Anisotropy of normally consolidated Boston blue clay,” ScD thesis, Massachusetts Institute of Technology, Cambridge, Mass.
17.
Sivakugan, N., Chameau, J. L., and Holtz, R. D.(1993). “Anisotropic studies on cuboidal shear device.”J. Geotech. Engrg., ASCE, 119(6), 973–983.
18.
Su, S. F., and Liao, H. J. (1997). “Anisotropic undrained strength criterion for saturated cohesive soil.”J. Chinese Inst. of Civ. and Hydraul. Engrg., 9(1), 57–64 (in Chinese). Summary report on the ground modification of Keelung River reclamation project . (1985). Moh and Associates, Taipei, Taiwan (in Chinese).
19.
Terzaghi, K. (1943). Theoretical soil mechanics. John Wiley and Sons, New York, N.Y.
20.
Tsai, J. S. (1994). “A thought from a soft ground excavation case.”Sino-Geotechnics, 45, 5–12 (in Chinese).
21.
Vaid, Y. P., and Campanella, R. G.(1974). “Triaxial and plane strain behavior of natural clay.”J. Geotech. Engrg. Div., ASCE, 100(3), 207–224.
22.
Wang, C. H. (1994). “Discussion on the base failure case on Kee-Her Road, Taipei.”Technol. of Architectural Engrg., March, 157–168 (in Chinese).
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 124 • Issue 9 • September 1998
Pages: 809 - 819
Copyright
Copyright © 1998 American Society of Civil Engineers.
History
Published online: Sep 1, 1998
Published in print: Sep 1998
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.