[TherapyforGlencross]

It’s not exactly surprising the bunkers weren’t destroyed.

The bomb weighs 14,000kg and is dropped from 12,000 meters, and let us assume that it may not reach terminal velocity and was not propelled it will smash into the ground with 1.65 billion Joules of energy.

Now, one blow from a SPT hammer is ~ 500 Joules. In engineering/geology refusal is 50 N counts (blows), which usually equates to 0.45 meters. Thus, 25,000 Joules of energy. The bomb would penetrate 28 meters into material that meets the SPT refusal requirements which would be considered hard clay.

The fordow complex is overlain by mountains, so let’s assume a dolostone/limestone mix. Using Young Equation (moreso a model), and you’re looking at approximately 6m penetration. Assuming that the limestone is deformed, you could potentially see a 100% increase, perhaps more, so about 10-15 meters of penetration.

Not exactly surprising to see the US admit that they didn’t collapse the entire structure.