Factors affecting soil characteristics under fast transients

It is well accepted that soil conduction under high magnitude impulse currents is affected by the magnitude of applied current, the type of soil, its moisture content. Also, a threshold electric field intensity (Ec) has been identified above which soil ionisation occurs. However, the published results (1-5) reveal wide range of values of Ec and the effects of many other factors such as impulse polarity, grain size and electrode geometry require further investigation. In this paper, we report test results on various soil media using impulses of negative polarity. The aim of this investigation was to extend an earlier study (6); by quantifying the effects of impulse polarity, grain size and threshold electric field ( Ec) on soil electrical properties.