John Lamont-Black, operations director, Electrokinetic Austin Weltman, geotechnical director, Tony Gee & Partners. This paper was first published in GE’s April issue.
Failed slopes in engineering soils are caused by a variety of factors including slope geometry, material strength, hydrology and groundwater, seasonal climate variations and the effects of vegetation and wildlife. Changes to rainfall patterns as a result of climate change are anticipated to exacerbate the problems.
The choice of repair method depends on site conditions, logistics and cost, and can include the acquisition of additional land, reducing the slope, installing additional drainage either as counterforts or horizontal drains, soil nailing and providing stability by structural methods. All these methods have their limitations and some are very costly.
Another alternative is the use of electrokinetic techniques, using electrically conductive geosynthetics. This technical note introduces the concept of electrokinetic geosynthetics (EKG) and shows how this technology can be used to strengthen and repair slopes insitu, and the resulting reductions both in cost and carbon footprint compared with other methods.