electrokinetics

Vikas Gingine Student M.Tech IV

Ravi Shah Student M.Tech IV

P. V. Koteswara Rao Research Scholar

Dr. P. Hari Krishna Associate Professor

Geotechnical Division, Civil Engg. Dept. NIT WARANGALNTCE-2013 VASAVI COLLEGE OF ENGG.

HYDERABAD

CONTENTS

NTCE-2013 VASAVI COLLEGE OF ENGG. HYDERABAD

introduction

SHRINKNTCE-2013 VASAVI COLLEGE OF ENGG.

HYDERABAD

Introduction EXPANSIVE SOIL/ B.C. Soil

• High swelling in wet seasons &High shrinkage in dry seasons.

• Montmorillonite


Introduction EXPANSIVE SOIL

• The expansive soil are often formed in the semi-arid region where there is enough water available to weather the parent rock but not quite enough to wash out the cations formed in that environment..

Damage:• Foundations• Pavements & railways tracks• Canals• Buried lifelines• Light Wt Structures• 6 BILLION DOLLARS in the U.S alone


Introduction FOUNDATON PRACTICES

• “Structural engineers and foundation experts state that there are two types of foundation owners, those who have had foundation problems and those who will.”

• Avoid expansive soil• Sand Cushion; C-N-S layer• Chemical treatment• Pad Foundations; Drilled pier; Belled pier; Friction Pier;

Under-Reamedpiles• Granular piles; Micropiles

etc.,NTCE-2013 VASAVI COLLEGE OF ENGG. HYDERABAD

Introduction ELECTROKINETICS

• The application of electroosmosis to improve the soil was demonstrated

by Casagrande (1952). Since then, the process has been applied to the

ground improvement in the field.

• Currently, electric potential is applied between anode and cathode, and

the chemical solutions are injected via the anode and/or cathode into the

soil for soil improvement.


Introduction ELECTROKINETICSAN

OD

ECATH

OD

E


SOILSOIL

Introduction ELECTROKINETICS

Electrokinetic Cementation:


Literature review


Review of past work

Electrokinetically treated soils

1. Eltayeb Mohamedelhassan , “Laboratory Model Test on Improving the Properties of soft clays by electrokinetics”, International Scholarly Research Network, ISRN Civil Engineering, Article ID 56083, Volume 2011.

2. Shenbaga R. Kaniraj ; J. H. S. Yee, “ Electro-Osmotic Consolidation Experiments on an Organic Soil”, Geotech Geol Eng (2011) 29:505–518


Review of past work


3. S. Micic, J Q. Shang and K. Y Lo, “Electrokinetic Strengthening of Marine Clay Adjacent to Offshore Foundations”, Proceedings of the Eleventh, International Offshore and Polar Engineering Conference.2001

4. Shenbaga R. Kaniraj, H. L. Huong , J. H. S. Yee, “Electro-Osmotic Consolidation Studies on Peat and Clayey Silt Using Electric Vertical Drain”, Geotech Geol Eng (2011) 29:277–295


Review of past work


5. S. Jayasekera , S. Hall, “Modification of the properties of salt affected soils using electrochemical treatments”,Geotech Geol Eng (2007) 25:1–10

6. Krishna R. Reddy, “Technical Challenges to In-situ Remediation of Polluted Sites”, Geotech Geol Eng (2010) 28:211–22


Amnart Rittirong, et al., “Effects of Electrode Configuration on Electrokinetic Stabilization for Caisson Anchors in Calcareous Sand.” ,Journal of Geotechnical and Geoenvironmental Engineering, Vol. 134, No. 3, March 1, 2008. ©ASCE

Review of past work

Foundations on electrokinetically treated soil


•Electrokinetic Properties of Expansive soil

•Electrokinetic treatment on Expansive soil

Review of past work


Review of past work

Electrokinetic Properties Expansive soils

Suat Akbulut, Seracettin Arasan, “The Variations of Cation Exchange Capacity, pH and Zeta Potential in Expansive Soils Treated by Additives.”, International journal of civil and structural engineering, Volume 1, No 2, 2010

• Three CH soils Samples around Turkey were tested

• Variation of the following properties of expansive soil treated with additives

Cement Lime Flyash Silica Flume

Cation Exchange Capacity

pH

Zeta Potential Slight changes for all additives


Review of past work

Electromigration in Expansive soil

Nahesson Hotmarama Panjaitan et al.,(2012), “The Phenomenon of Electromigration During Electrokinetic Process On Expansive Clay Soil”, International Journal of Civil & Environmental Engineering IJCEE-IJENS Vol:12 No:04

• The positive charged ion will move toward the cathode and ion charge negative moves to the anode.

• Future Scope to determine the influence of the phenomenon of electromigration, such as atterberg limit test, swelling test and strength of soil test NTCE-2013 VASAVI COLLEGE OF ENGG.

HYDERABAD

Review of past workElectrokinetic improvement of an Expansive soil

Samudra Jayasekera, “Stabilising volume change characteristics of expansive soilsusing electrokinetics a laboratory based investigation”,Sri Lankan Geotechnical Society's First International Conference, Colombo, Sri Lanka : 5th-11th August 2007


Review of past workElectrokinetic improvement of an Expansive soil

W.S. Abdullah ,A.M. Al-Abadi (Jordan), “Cationic–electrokinetic improvement of an expansive soil”, Applied Clay Science 47 (2010) 343–350

Ca(OH)2

CaCl2

KOH

KCl NTCE-2013 VASAVI COLLEGE OF ENGG.

HYDERABAD

Review of past work

Review of Setups

In field applications, the voltage gradient typically ranges from 10 to 200 V/mNTCE-2013 VASAVI COLLEGE OF ENGG.

HYDERABAD

• Eletroosmosis & Electromigration

• ElectroCementation

Formation of ferrous or aluminium oxides in the soil, which

are natural cementing agents.

• Improvement in the swelling properties of the expansive soil

after the treatment.

• 15mm of soil layer was firmly attached to the metal objects

Review of past work

Points to be noted


Need & SCOPE


references1. Abdullah,W.S., Al-Abadi, A.M. (2010),“Cationic–electrokinetic improvement of an expansive soil”,

Applied Clay Science 47, 343–350.2. Albert Yeung (2011), “Milestone developments, myths, and future directions of electrokinetic

remediation”, Separation and Purification Technology, Elsevier 79,124–132.3. Amnart Rittirong et al. (2008), “Effects of Electrode Configuration on Electrokinetic Stabilization for

Caisson Anchors in Calcareous Sand.” Journal of Geotechnical and Geoenvironmental Engineering, Vol. 134, No. 3,©ASCE

4. Beni Lew (2010), “Structure Damage Due to Expansive Soils: a Case Study”, Electronic Journal of Geotechnical Engineering Vol. 15, Bund. M pp-1317-1324.

5. Chen F. H. (1975), Foundations on Expansive Soils, 1st ed., Elsevier Publishers, Amsterdam Netherlands.6. Colin.J.F.P.Jones (2011),“Electrokinetic geosynthetics in hydraulic applications”, Geotextiles and

Geomembranes, Elsevier,29 381-390.7. Eltayeb Mohamedelhassan (2011), “Laboratory Model Test on Improving the Properties of soft clays by

electrokinetics”, International Scholarly Research Network, ISRN Civil Engineering, Article ID 560834,14 pages

8. Hari Krishna P and Ramana Murty (2013), “Pull-Out Capacity of Granular Anchor Piles in Expansive Soils”, IOSR Journal of Mechanical and Civil Engineering, Volume 5, Issue 1 pp 24-31.

9. I.S: 2911(Part III)(1980). Indian Standard Code of Practice for Design and Construction of Pile Foundations, Under reamed Piles, Bureau of Indian standards, New Delhi

10. Katti, R. K. (1979) “Search for Solutions for Problems in Black Cotton Soils” Indian Geotechnical Jrl. 9(1), 1–80


references11. Krishna Reddy et al.(2004), “Iodide-Enhanced Electrokinetic Remediation of Mercury-Contaminated

Soils”, Journal Of Environmental Engineering © ASCE, 129:1137-1148

12. Krishna Reddy(2010), “Technical Challenges to In-situ Remediation of Polluted Sites”, Geotechnical and Geological Engineering, 28:211–22

13. Lucas Adamson et al.(1966),“Electrokinetic Dewatering, Consolidation And Stabilization Of Soils”, Engineering Geology, 1 (4),291-304

14. Mohammad Ali, Shaik Moin Ahmed(2011),“Micropile technique to control heave on expansive soils”, Proceedings of Indian Geotechnical Conference, Kochi (paper No. D311)

15. Nahesson Hotmarama Panjaitan et al.,(2012),“The Phenomenon of Electromigration During Electrokinetic Process On Expansive Clay Soil”, International Journal of Civil & Environmental Engineering IJCEE-IJENS Vol:12 No:04

16. Nasim Mosava et al.(2012),“A Review of Electrokinetic Treatment Technique for Improving the Engineering Characteristics of Low Permeable Problematic Soils”, International Journal of GEOMATE, Vol. 2, No. 2 (Sl No.4) pp 266-272

17. Osama K. Nusier and Ahmed Shlash Alawneh (2004), “Micropile technique to control upward movement of lightweight structures over expansive soils”, Geotechnical and Geological Engineering 22: 89–104.

18. Phani Kumar, B.R., Sharma, R.S., Srirama Rao, A, Madhav,M.R. (2004). Granular Pile–Anchor Foundation (GPAF) System for Improving the Engineering Behaviour of Expansive Clay Beds. (ASTM) Geotechnical Testing Jrl.27, (3), 279 – 287

19. S. Micic et al.,(2003), “Electrokinetic Strengthening of Soil Surrounding Offshore Skirted Foundations” Proceedings of the Thirteenth International Offshore and Polar Engineering Conference. pp 665-672.


references20. Shenbaga R. Kaniraj et al.(2011), “Electro-Osmotic Consolidation Studies on Peat and Clayey Silt Using

Electric Vertical Drain”, Geotechnical and Geological Engineering 29:277–295.21. Shenbaga R. Kaniraj, J.H.Yee (2011), “Electroosmotic Consolidation Experiments on an Organic Soil”,

Geotechnical and Geological Engineering, 29:505–518.22. Sivapullaiah, P.V. (2007),“Electroosmotic flow behaviour of metal contaminated expansive soil”, Journal

of Hazardous Materials 143, Elsevier, pp 682–68923. Soon-Oh Kim(2004), “Evaluation of Electrokinetic Removal of Heavy Metals from Tailing Soils”, Journal

Of Environmental Engineering, ASCE 128:705-715.24. Suat Akbulut, Seracettin Arasan(2010),“The Variations of Cation Exchange Capacity, pH and Zeta

Potential in Expansive Soils Treated by Additives”, International journal of civil and structural engineering, Volume 1, No 2.

25. Samudra JayasElectrokineticera, (2007), “Stabilising volume change characteristics of expansive soils using electrokinetics a laboratory based investigation”, Sri Lankan Geotechnical Society's First International Conference, Colombo, Sri Lanka.

26. Samudra JayasElectrokineticera , S. Hall(2007), “Modification of the properties of salt affected soils using electrochemical treatments”, Geotechnical and Geological Engineering, 25:1–10

27. Satyanarayana, B (1969), “Behaviour of Expansive Soil treated or Cushioned with Sand” Proc. 2nd Intl. Conf on Expansive soils. Texas A & M Univ, Texas, 308 – 316

28. Shao-Chi Chien; Chang-Yu Ou (2011) “A novel technique of harmonic waves applied electro-osmotic chemical treatment for soil improvement” Applied Clay Science, Elsevier 52, 235–244NTCE-2013 VASAVI COLLEGE OF ENGG.

HYDERABAD

THANK YOU ALL


Energy Consumption

For the application of constant applied voltage the energy consumption per unit volume of treated soil during a test, W (Wh/m3), can be evaluated based on the following relationship:

where V o - applied voltage (V); x - current intermittence ratio; tp~ - treatment time under one polarity (hours) (i=l, 2, ....,NR); NR - number of polarity reversal (NR=I for no reversal); I (t) - electric current as a function of time t (A); v - volume of treated soil v = Ax H (m3); A - treatment area (m2); and H - electrode insertion depth (m


• Current Intermittence


• The expansive soil are often formed in the semi-arid region where there are enough water available to weather the parent rock but not quite enough to wash out the cations formed in that environment.


• The third phase of a test, i.e., diffusion, lasted 45 days. After

• electrokinetic treatment, the soil samples were set aside and sealed to

• further study the post-treatment effects due to the ionic diffusion and

• other electrochemical reactions


Cation Exchange CapacityBache [37] method was used in this study because of its simplicityThe soil samples, which dried at 105 and weighed 5 gr, were saturated to Na + with sodium acetate (CH3COONa.3H2O) solution (1 N) at pH 8.2.When the samples were fully saturated with Na + , ethanol (95%) was used to wash out excesssalt and the Na + cations were replaced with NH4 + by using a ammonium acetate (CH3COONH4) solution (1 N) at pH 7.0. Then, the amount of sodium in the solution was determined by the atomic adsorption method and the cation exchange capacity of the samples was calculate with equation:

Where; Nf is concentration of sodium ion in extract, D is density coefficient of ammonium acetate solition, and W is oven dry sample weight (g).


11. Electrokinetic CementationElectrode reactions mainly control electrokinetic cementation.The steel anode releases ferrous ions Fe2+ into seawater, and theelectrode is corroded byquilibrium controls the precipitation of dissolved ironPourbaix 1966; Whittemore and Langmuir 1975. The precipita-tion of ferrous and ferric ions results in iron-rich cements in thecalcareous sand


• 11.• First,• the caisson was used as a cathode to generate alkaline environ-• ment surrounding the caisson, enhancing the precipitation of dis-• solved metals. The electrode polarity was then reversed so that• the caisson became an anode and released iron ions, which were• precipitated as iron-rich cement on the caisson shaft and soil in-• terface. It has been reported that current intermittence can im-• prove the treatment effectiveness and reduce energy consumption


electrokinetics

Documents

vasavi college of engg

civil engg

soil improvement

organic soil

hyderabadthe expansive

offshore foundations

geotech geol eng

foundation problems