Electrokinetic applications to stabilise shrink swell characteristics of expansive soils

PROJECT TITLE: 

ELECTROKINETIC APPLICATIONS TO STABILISE SHRINK SWELL CHARACTERISTICS OF EXPANSIVE SOILS

PROJECT OUTLINE:

Expansive soils are found extensively throughout the world almost in every continent, mainly in the semi-arid regions of tropical and temperate zones. In Australia, it is reported that approximately 30 per cent of all dwellings and approximately 50 per cent of Victoria’s surface area is covered by moderate to highly expansive soils.

These soils undergo volume changes (shrinkage and swelling) which are typically cyclic, and cause destructive and significant structural damages to light structures (residential buildings, roads) built on them.

The shrink-swell characteristics of expansive soils are difficult to improve. The most common treatment technique is chemical stabilisation using different combinations of additives such as lime, cement, fly ash etc. However use of this technique is limited for reasons of time, access and depth constraints. Therefore, at present, the only feasible strategy to combat the detrimental effects of expansive soils on infrastructure appears to be living with and adapting to it by using of higher grade construction materials and more extensive construction practices. The Australian Standard ‘AS 2870: Residential Slabs and Footings’ recommends relatively extensive and expensive foundation systems to all residential buildings constructed on expansive soils in Australia.

The use of electrokinetic (EK) methods is a viable in situ soil remediation and treatment technique that is practised successfully in some parts of the Europe and US. In this project, it is planned to investigate the potential of EK methods to stabilise volume change (shrink-swell) characteristics of expansive soils. The findings could lead to significant environmental and economic benefits to residential building construction Industry in Australia.

REFERENCES

Samudra Jayasekera (2008) –An Investigation into Modification of the Engineering Properties of Salt Affected Soils Using Electrokinetics, PhD Thesis – University of Ballarat

Jayasekera, S. (2007) “Modification of the Properties of Salt Affected Soils using Electrochemical Treatments” International Journal of Geotechnical and Geological Engineering (Springer)

Jayasekera, S. (2015) ‘Electrokinetics to Modify Strength Characteristics of Soft Clayey Soils: A Laboratory Based Investigation’, Electrochimica Acta, Elsevier

PROJECT SUPERVISION TEAM

Samudra Jayasekera 

Thomas Baumgartl)