Investigation of wave propagation penetraion depth in multi-layer ground

This paper studies penetration depth and wave propagation in multi-layer ground. A relation between a wave propagation domain frequency, penetration dpeth and multi-layer ground parameters is estimated. An experimental setup is constructed to study the transient characteristics of spherical grounding electrode embedded into ground. The ground is analysed as homogenous ground, two-layer ground and multi-layer ground. To verify the proposed equations, a spherical grounding electrode is tested by injecting a step like current of different rise times into the spherical grounding electrode at different depths. The injected currents and voltages are measured and analysed. The electrode impedance shows dependence on the injected domain frequency and depth of the spherical grounding electrode at different ground layers. Numerical model is proposed by using the current source simulation method and the method of successive image technique. This model is used to investigate the penetration depth effects on grounding spherical electrode resistance in homogenous and two-layer ground. The experimental results verify the proposed estimated penetration depth equations.