Nonsense. Ordinary heavy walled bombs can do it easily, if used properly. Here is how:

1. Drop a precision guided bomb on target A. It does not go all the way through, but makes a crater, removing a layer of compacted earth and some reinforced concrete.

2. Drop another precision guided bomb on target A at exactly the same place. It enters the crater left by the previous ordnance before hitting solid earth or concrete. It peels off another few meters of cover.

3. Repeat step 2 until the hole is of the desired depth. Each bomb removes the rubble of previous bombs and goes deeper. There is simply no limit as to how deep one can make a hole that way. The last bomb goes off INSIDE the facility, destroying it.

This is analogous to the way mining works. You drill a hole. Plant explosives. Detonate the explosives. Remove the rubble and do it over.