How strong, thick, long and deep would a subterranean wall have to be to be effective?
Question for an engineer. Deep enough to make a tunnel impractical given the resources that Ghazans presumably are limited to.
How strong, thick, long and deep would a subterranean wall have to be to be effective?
= = =
Maybe it is not a wall, but a spaced set of acoustic sensors, composing a 3-d grid to triangulate any detected ‘sound’ or activity.
Meanwhile, there are buried charges that can be selectively detonated at the appropriate location (my enhancement).