Conductance Between Two Strip Electrodes on a Conducting Ground with a Nearby Tunnel

The zero-frequency problem of a pair of perfectly-conducting strip electrodes lying on an imperfectly conducting half-space and perturbed by the presence of a nonconductive cylindrical void or tunnel is analyzed. A conformal mapping transforms all of the pertinent boundaries in the potential problem to simple coordinate surfaces in a single cylindrical coordinate frame. Coupled integral equations for the normal electric current density on each strip are numerically solved using the moment method. The effect upon the circuit resistance of various sized subsurface tunnels at arbitrary locations is now easily calculable.