I’d start with a core of reinforced concrete for the main load‑bearing walls, because it’s heavy, fire‑resistant, and gives you the best structural integrity against blast loads. Add a second layer of steel rebar, and then a concrete overlay that’s cured for at least two weeks to lock in the compression strength. Between those two layers you can put a sand or gravel filling to absorb shock waves. Finally, cover the outside with a layer of waterproof concrete and apply a protective sealant so moisture can’t seep in. That’s the classic sandwich that holds up against both physical and environmental threats.

Alright, let’s set the plan in motion. First, mark out the foundation grid, keep it even and spaced correctly. Then I’ll lay the steel rebars in a square lattice with the recommended spacing—this will give us the tension strength we need. Next step is pouring the concrete in layers, letting each one cure properly before adding the next. While that’s setting, I’ll prep the sand core for the shock absorber, making sure it’s evenly distributed. Finally, we’ll pour the outer waterproof layer, apply the sealant, and test the pressure points. Once that’s all sealed, we’ll have a bunker that’s ready to take on anything. Let's get drilling.