Let's say we did an experiment and went into a modern neighborhood and cut the GEC in-between the house and the grounded/Ufer. What would be the issues that we might see pop up over time?
A connection to earth is holy in this field of work, but I am trying to understand what it's actually doing. I find it interesting that two ground rods in a rocky trench backfilled with dry rubble are treated the same as the same two driven into moist clay. Same goes for a Ufer in a house built on bedrock. It's like we're just going through the motions.
I am here to learn, so anything you have to add on this topic is appreciated.
If you cut the GEC at one house, most likely no one will ever notice a difference.* If you cut the GEC at all the houses in the neighborhood, people might notice an increased likelihood of damage to electronics due to lightning or high-voltage surges from utility problems.
*Since you said 'modern' neighborhood, we could take that to mean that there isn't a metal water pipe distribution system that connects all the houses' grounding to each other. Meaning that what happened to Buck in post #11 won't happen to you. But what he described is a good reason to check that your GEC isn't carrying a surprisingly high number of amps before you cut it. Especially in older neighborhoods.
I agree that there is a certain amount of going through the motions involved. But if everybody stopped grounding everywhere, that would probably be bad.
I wonder why we are not required to prove that the electrode has an effective path? Or maybe in some places you are?
Because that would be a much bigger pain-the-butt than it is worth. Basically, if the vast majority of the grounding out there does a little bit of something most of the time, then it's doing its job. It isn't so critical to test every component of it for perfection. Mike Holt has some videos out there where he tests the resistance of electrodes, in case you want to see what it involves.
My question still stands about a house built on rock. Will the Ufer have any connection to ground in this case? Maybe soil backfilled around the foundation is enough? I ask because we actually see this a lot in my area. I have never tested a Ufer like this myself.
The ground is the ground, i.e. the earth (NEC definition!) and rock is just as much a part of it as soil. So the NEC does not care. Depending on the composition of the rock it may or may not be all that much less conductive than soil, especially for the purposes of detecting high voltage utility faults.
