Abstract
Electrokinetic stabilization is an innovative and cost effective ground improvement method for soft soils. With this method, stabilizing agents are electrically injected into the soils to achieve stabilization by means of ion exchange, precipitation or mineralization. The method is not yet widely accepted for common application as it improves the strength of soils only within a limited area. When coupled with a depolarization technique, the quality of the soil improvement is enhanced. Calcium ions are electrically injected into soils to replace monovalent ions while hydrogen ions, generated from electrolysis at the anode, are prevented from migrating into soils by continuous depolarization at the anode reservoir. However, hydroxide ions, generated at the cathode, are able to migrate into the soils. The injected calcium ions and hydroxide ions react with the dissolved silicates and aluminates in the clay to form cementing agents—calcium silicates and/or aluminum hydrates. Increases in strength of up to 170% immediately after treatment and up to 570% after a 7-day curing were measured. These results demonstrate that this simple technique could significantly improve the quality of electrokinetic stabilization in soft soils.
Résumé
La stabilisation électrocinétique est une méthode innovante et économique d’amélioration des sols mous. Par cette méthode, des agents chimiques sont injectés électriquement dans le sol pour obtenir une stabilisation grâce à des processus d’échanges ioniques, de précipitation et de minéralisation. La méthode n’est pas encore largement appliquée dans la mesure où l’amélioration de la résistance du sol ne se réalise que dans une zone limitée. Les ions calcium sont électriquement injectés dans le sol et remplacent des ions monovalents, tandis que les ions hydrogène, résultant de l’électrolyse et produits à l’anode, ne peuvent migrer dans le sol du fait de la dépolarisation continue à l’anode. Cependant, les ions hydroxyde, produits à la cathode, peuvent migrer dans le sol. Les ions calcium injectés et les ions hydroxyde réagissent avec les silicates et aluminates dissous, provenant des argiles, pour former des agents de cimentation – des silicates de calcium et/ou des hydrates d’aluminium. Des augmentations de résistance jusqu’à 170% immédiatement après le traitement et jusqu’à 570% après un traitement de 7 jours ont été mesurées. Ces résultats démontrent que cette technique simple pourrait améliorer de façon significative la qualité de la stabilisation électrocinétique des sols mous.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Acar YB, Hamed J, Alshawabkeh A, Gale R (1994) Cd(II) Removal from saturated kaolinite by application of electrical current. Gèotechnique 44:239–254
Alshawabkeh AN, Sheahan TC (2003) Soft soil stabilisation by ionic injection under electric fields. Ground Improv 7:177–185
Assarson K, Broms B, Granholm S, Paus K (1971) Deep stabilization of soft cohesive soils. Linden Alimark, Sweden, p 20
Baker JE, Rogers CDF, Boardman DI, Peterson (2004) Electrokinetic stabilization: an overview and case study. Ground Improv 8:47–58
Bergado DT, Lorenzo GA, Balasubramaniam AS (2000) A comparison of engineering behavior of cement treated and lime treated soft Bangkok Clay. In: Proceedings of the 12th Asian regional conference on soil mechanics and geotechnical engineering, vol 1, pp 449–452
Diamond S, Kinter EB (1965) Mechanisms of soil-lime stabilization—an interpretative review. Highway Res Rec 92:83–102
Esrig MI, Gemeinhardt JP (1967) Electrokinetic stabilization of an illitic clay. J Soil Mech Found Eng Div ASCE 93:109–128
Eykholt GR (1997) Development of pore pressures by nonuniform electroosmosis in clays. J Hazard Mater 55:171–186
Eykholt GR, Daniel DE (1994) Impact of system chemistry on electroosmosis in contaminated soil. J Geotech Eng ASCE 120:797–815
Gray DH (1970) Electrochemical hardening of clay soils. Géotechnique 20:81–93
Hamed JT, Bhadra A (1997) Influence of current density and pH on electrokinetics. J Hazard Mater 55:279–294
Kamruzzaman AHM (1998) Chemical stabilization of Bangkok Clay: addition of salts and other additives. Asian Institute of Technology, Bangkok, p 34
Mohamedelhassan E, Shang JQ (2002) Effect of electrode materials and current intermittence in electro-osmosis. Ground Improv 5:3–11
Ozkan S, Gale RJ, Seals RK (1999) Electrokinetic stabilization of kaolinite by injection of Al and PO 3−4 ions. Ground Improv 3:135–144
Page MM, Page CL (2002) Electroremediation of contaminated soils. J Environ Eng ASCE 128:208–219
Segall BA, Bruell CJ (1992) Electroosmotic contaminant-removal processes. J Environ Eng ASCE 118:84–100
Wada S-I, Umegeki Y (2001) Major ion and electrical potential distribution in soil under electrokinetic remediation. Environ Sci Technol 35:2151–2155
West LJ, Steward DI, Binley AM, Shaw B (1999) Resistivity imaging of soil during electrokinetic transport. Eng Geol 53:205–215
Yeung AT, Sade SM, Mitchell JK (1992) A new apparatus for the evaluation of electro-kinetic processes in hazardous waste management. Geotech Test J 15:207–216
Yeung AT, Scott TB, Gopinath S, Menon RM, Hsu C-N (1997) Design, fabrication, and assembly of and apparatus for electrokinetic remediation studies. Geotech Test J 20:199–210
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Asavadorndeja, P., Glawe, U. Electrokinetic strengthening of soft clay using the anode depolarization method. Bull Eng Geol Environ 64, 237–245 (2005). https://doi.org/10.1007/s10064-005-0276-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10064-005-0276-7