Overview

EKG Embankment Construction

EKG Soil Nails and Horizontal Drains

EKG Counterfort Drains

EKG Geochemical Soil Improvement

Environmental Sustainability

EKG counterfort drains

This product is under development and is not yet available commercially. However, the development is described below and is described in more detail in Jones et al 2008, in the downloads page.

The use of counterfort drains has been widespread because of their general ease of installation. Their anticipated function is to drain the soil and sometimes provide reinforcement against forces driving shear failure. However, they are not always successful (success being by the arresting of slope movement), particularly when installed in clay slopes.

The use of electrokinetic geosynthetics or EKG as filtration materials lining counterfort drains is an option to improve performance. This can be achieved by:

• Inducing electroosmotic flow from the soil to the counterforts

• Leveraging pore pressure differences created by electroosmotic flow to wet the clay surfaces of the counterforts, thus to overcome surface tension factors which can inhibit water flow across significant grain-size boundaries

• Induce zones of suction near the counterforts to steepen the hydraulic gradient towards the counterfort drains.

In the concept suggested, EKG materials would require only modest power at low voltages and would probably benefit from intermittent operation. As such a renewable power source, such as a wind or solar generator may be considered.

The photograph on the below shows a counterfort drain being lined with a conventional geosynthetic filter. The concept is to replace the conventional geosynthetic with an EKG and install anodes between the trenches (shown as red spots). An electric field set up between the anodes and the cathode lining the trench would have the effect of driving water towards the trench.

	A. Geosynthetic liner of the counterfort		B. Finished slope