Scientific Quarterly Journal of Iranian Association of Engineering Geology

Scientific Quarterly Journal of Iranian Association of Engineering Geology

Evaluation of improvement of mechanical resistance of fine soils due to the intrusion of calcium ions by means of electro kinetic method

Document Type : Original Article

Authors
1 Associated Prof., Soil Conservation and Watershed Management Research Institute, Tehran-Iran,
2 M.Sc. in Soil Mechanics
Abstract
Many fine grain soils suffer from low shearing resistance and need to be improved. In cases the treatment is done using additive materials such as calcium ion, the process is time consuming and any accelerating process is highly valuable. In this article the feasibility of using electro kinetics for intruding reinforcing calcium ions into fine soil, in order to improve its mechanical resistance, is studied. Soil sample were prepared under equal conditions and a calcium chloride solution of 0.66 normal were permeated through them under direct current electricity (DC). Then a series of mechanical and chemical tests were conducted on soil samples and input-output solutions, respectively. Resistance parameters of the soil were measured by means of direct shear test, before and after permeation of calcium chloride solution. The results reveal that this method has an extraordinary effect in increasing the level of calcium absorption in soil along with its mechanical resistance. The cohesion and the internal friction angle of treated soil increased to 220% and 92% respectively under a voltage of 30 volts. This increase in resistance parameters was gained by permeating just one soil porous volume (Vv) of solution. The weight of added calcium chloride to the soil was just as much as 0.9 % of the dry weight of the sample.
Keywords
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داودی، م.ه.، سیاوش­نیا، م.، احدی­عالی،و.، 1387. اصلاح خاک بسترهای تورم­زا در شبکه­های آبیاری و تثبیت بسترهای لغزشی کانال­های انتقال آب با استفاده از محلول اشباع آهک. اولین سمینار ملی مسائل ژئوتکنیکی شبکه­های آبیاری و زهکشی، ص. 288-281.
احدی­عالی، و.، 1386. پایدارسازی توده­های ناپایدار به­روش افزودن محلول اشباع آهک (مطالعۀ موردی تودۀ دنبلید شرقی طالقان). پایان نامه کارشناسی ارشد، دانشگاه آزاد اسلامی واحد تهران مرکزی، تهران.
رستمی، م.، 1389. بررسی تأثیر محلول اشباع آهک بر افزایش مقاومت فشاری خاک­های رسی. پایان نامه کارشناسی ارشد، دانشگاه آزاد اسلامی واحد تهران مرکزی، تهران.
الوندکوهی، 1385. افزایش مقاومت برشی خاک از یک توده طبیعی لغزشی با استفاده از چاهک­های حاوی آب و آهک. پایان نامه کارشناسی ارشد، دانشگاه آزاد اسلامی واحد تهران مرکزی، تهران.
Abdullah, W.S., Al-Abadi, A.M., 2010. Cationic–electrokinetic improvement of an expansive soil. Journal of Applied Clay Science, 47: 343–350.
Canadian Geotechnical Society, 1987. Canadian Foundation Engineering Manual.
Sherwood, P.T., 1993. Soil Stabilization with Cement and Lime. State of the Art Review, HMSO, London UK.
Mitchell, J.K., 1993. Fundamentals of Soil Behavior. John Wiley & Sons, Inc, pp. 229-270
Fang, H., 2004. Foundation Engineering Handbook. CBS Publisher & Distributors, pp. 350-351.
Yu Ou, C., Chi Chen, S., Guang Wang, Y., 2009. On the enhancement of electro-osmotic soil improvement by the injection of saline solution. Journal of Applied Clay Science,
Acar, Y.B., 1992. Electrokinetic Soil Processing. ASCE, Geotechnical Special Publication, 30
Volume 4, Number 1 & 2
September 2011
Pages 47-60

  • Receive Date 17 December 2011
  • Revise Date 19 January 2012
  • Accept Date 22 February 2012