Slope Stability of Embankments on Soft Soil Improved with Vertical Drains
The overloads of structures or embankments built on clayey soft ground are generally applied gradually, respecting a specific phasing. This phasing on construction allows the undrained shear strength of clay increasing over consolidation in order to avoid the risk of collapse during loading. In this work, the undrained shear strength of clay over the consolidation was estimated following SHANSEP method of which parameters proposed by eight researchers have been employed, as well as the slope stability analysis of embankments on soft soils during staged construction. Assessment of factor of safety for slope stability was conducted basing on the Bishop method. Additionally, the variations of undrained shear strength and factor of safety were presented. In order to validate the methods discussed in this study, slope stability analysis of five embankments constructed on clayey soft soils improved by the vertical drain technique in a high-speed railway construction project in Morocco was performed. For these embankments, field measurements about lateral displacement are presented. It was found that some of the adopted methods is in a good agreement with field measurements. Hence, generalization of these methods to many soft ground cases can be proposed.
Skempton, A. W. "The post-glacial clays of Thames estuary at Tilbury and Shell-haven." In Proc., 3rd ICSMFE, vol. 1, pp. 302-308. 1953.
Bjerrum, Laurits. "Comparison of shear strength characteristics of normally consolidated clays." Norwegian Geotechnical Institute. Publication 35 (1960): 13-22.
Karlsson, R., and L. Viberg. "Ratio c/p'in relation to liquid limit and plasticity index with special reference to Swedish clays." Swedish Geotechnical Inst Reprints & Repts (1967).
Janbu, N. “Soil Models in Offshore Engineering.” Géotechnique 35, no. 3 (September 1985): 241–281. doi:10.1680/geot.19220.127.116.11.
Mesri, Gholamreza. "New design procedure for stability of soft clays." Journal of Geotechnical and Geoenvironmental Engineering 101, no. Discussion (1975).
Jamiolkowski, Michele. "New developments in field and laboratory testing of soils," State of the Art Report." In Proc. 11th Int. Conf. on SMFE, vol. 1, pp. 57-153. 1985.
Mayne, Paul W., and James K. Mitchell. “Profiling of Over consolidation Ratio in Clays by Field Vane.” Canadian Geotechnical Journal 25, no. 1 (February 1, 1988): 150–157. doi:10.1139/t88-015.
Ladd, Charles C. "Stability evaluation during staged construction." Journal of Geotechnical Engineering 117, no. 4 (1991): 540-615. doi:10.1061/(ASCE)0733-9410(1991)117:4(540).
Indraratna, Buddhima, A. S. Balasubramaniam, and S. Balachandran. "Performance of test embankment constructed to failure on soft marine clay." Journal of Geotechnical Engineering 118, no. 1 (1992): 12-33. doi: 10.1061/(asce)0733-9410(1992)118:1(12).
Mohd Amin, J., M. R. Taha, J. Ahmed, A. Abu Kassim, A. Jamaluddin, and J. Jaadil. "Prediction and determination of undrained shear strength of soft clay at Bukit Raja." Pertanika Journal of Science & Technology 5, no. 1 (1997): 111-125.
Roy, Debasis, and Raghvendra Singh. "Mechanically stabilized earth wall failure at two soft and sensitive soil sites." Journal of performance of constructed facilities 22, no. 6 (2008): 373-380. doi: 10.1061/(asce)0887-3828(2008)22:6(373).
David Suits, L, TC Sheahan, TH Seah, and KC Lai. “Strength and Deformation Behavior of Soft Bangkok Clay.” Geotechnical Testing Journal 26, no. 4 (2003): 8933. doi:10.1520/gtj11260j.
D’Ignazio, M., and T. Länsivaara. "Strength increase below an old test embankment in Finland." In Proceedings of the Nordic Geotechnical Meeting (NGM) 2016, Reykjavik, Iceland, vol. 1, pp. 357-366. 2016.
Persson, Erik. "Empirical correlation between undrained shear strength and preconsolidation pressure in Swedish soft clays." (2017).
Ding, Dan, and J. Erik Loehr. “Variability and Bias in Undrained Shear Strength from Different Sampling and Testing Methods.” Journal of Geotechnical and Geoenvironmental Engineering 145, no. 10 (October 2019): 04019082. doi:10.1061/(asce)gt.1943-5606.0002121.
Mesri, Gholamreza, and Cai Wang. “Discussion of ‘Correlations for Undrained Shear Strength of Finnish Soft Clays.’” Canadian Geotechnical Journal 54, no. 5 (May 2017): 745–748. doi:10.1139/cgj-2016-0686.
D’Ignazio, Marco, Kok-Kwang Phoon, Siew Ann Tan, Tim Länsivaara, and Suzanne Lacasse. “Reply to the Discussion by Mesri and Wang on ‘Correlations for Undrained Shear Strength of Finnish Soft Clays.’” Canadian Geotechnical Journal 54, no. 5 (May 2017): 749–753. doi:10.1139/cgj-2017-0114.
Lechowicz, Zbigniew, Simon Rabarijoely, and Tetiana Kutia. “Determination of Undrained Shear Strength and Constrained Modulus from DMT for Stiff Overconsolidated Clays.” Annals of Warsaw University of Life Sciences – SGGW. Land Reclamation 49, no. 2 (June 1, 2017): 107–116. doi:10.1515/sggw-2017-0009.
Lawane, Abdou, Nadjibou Abdoulaye Hama, Marie Thèrese Gomis, Adjoudou Ngnintedem Maruis, and Adamah Messan. "Correlation Between Shear Strengths of Disturbed and Undisturbed Soils at Three Sites in Burkina Faso." Advances in Materials 7, no. 4 (2018): 128.
Carrillo, Nabor. “Simple Two and Three Dimensional Case in the Theory of Consolidation of Soils.” Journal of Mathematics and Physics 21, no. 1–4 (April 1942): 1–5. doi:10.1002/sapm19422111.
L. Ménard, “Mesures in situ des propriétés physiques des sols,” Ann. Ponts Chaussées, vol. 1, no. 3, pp. 357–376, 1957.
S. Amar and J. F. Jézéquel, “Essais en place et en laboratoire sur sols cohérents: comparaison des résultats,” Bull. Liaison Ponts Chaussées, vol. 58, pp. 97–108, 1972.
M. Cassan, “Les essais in situ en mécanique des sols,” Eyrolles Eds, vol. 1, 1978.
F. Baguelin and J. F. Jézéquel, “Le pressiomètre autoforeur,” Ann Inst Tech Bâtim Trav Publics, vol. 1, pp. 307–308, 1973.
L. Bjerrum, “Embankments on soft ground,” Proc ASCE Spec. Conf. Earth Earth-Support. Struct. Purdue Univ., vol. 2, pp. 1–54, 1972.
F. Kassou, J. Benbouziyane, A. Ghafiri, and A. Sabihi, “Settlements and Consolidation Rates under Embankments in a Soft Soil with Vertical Drains.” International Journal of Engineering 30, no. 7 (July 2017). doi:10.5829/ije.2017.30.07a.06.
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