The experimental investigations on earth electrodes were carried out an outdoor site prior to electrode testing the test site soil resistivity were undertaken. Specifically, the soil resistivity was obtained at the location of the vertical test rod. In order to obtain better understanding of the soil stratification, fourteen profiles of soil resistivity were measured at the field site. From the measurements 2D soil models were constructed to visualise both horizontal and vertical resistivity variation.

 It was observed that when a sufficiently high current magnitude is injected through vertical electrodes, a significant reduction in the impulse resistance by increase in current with a sudden fall of voltage is observed which is called soil ionisation. Such phenomenon does not occur when the vertical electrodes with horizontal enhancements is tested, where the current through all earth electrodes is small.

Dear Prem Baboo,

Thank you for replaying to my question, and also for the documentation and for the explanation. I forgot to indicate that I work with impulse current (fast rise-time). For this purpose, I seek expression which allows us to estimate the apparent resistivity to use in therm of simulation without making measurements. I consider that I had the soil parameters (of each layer) and I am interested in how to find the apparent resistivity for each electrode structure.

Using TLM, this parameter is very important to calculate the distributed line parameters. If you have any other work, please share it with me.

Best regards,

Omar

Considering  that ρ1 > ρ2 (top and bottom layer resistivity, reps.), How to estimate the apparent resistivity for vertical electrodes for: the boundary depth greater, equal and/or less than l the burial depth.

The relationship in the second attached give an expression for horizontal electrodes, can we use it for vertical ones?

Thank you

Dear Omar Kherif,

Please find attached herewith useful article,

regards,

Prem Baboo

Dear;

for more information please check the following documents

• 2014MousaSPhD.pdf
• Soil-Resistivity-Data-Computations-Single-and-Two---Layer-Soil-Resistivity-Structure-and-Its-Implication-on-Earthing-Design.pdf

Regards

Dear;

for more information please check the following documents :

• download.jpg
• images.jpg
• Regards