What you suggest would slow them down for a year or so ... but if the contents of the bunkers stays in tact - then it can be rebuilt and restaffed - at great hardship I agree - but they can bet back on line ...
The one thing that occurs to be - bunker buster MOAB or bigger - then place multiple ones on the same site ... Make a big hole with one then follow up with two-three more - with GPS - TV guidance and laser guidance it can be done ... then nothing could withstand multiple hits - because the second and third start to blast at much deeper levels ...