Each Vivos complex is engineered, built and equipped to survive or substantially mitigate virtually all of the envisioned threats. The hardened shelters are buried deep below the Earth surface and are able to withstand a 20 megaton nuclear blast within a 10 mile radius.  They are engineered to protect from a radiation fallout, a biological or chemical attack, a solar flare, an electromagnetic pulse, submersion from a mega-tsunami, multiple force 10 earthquakes on the Richter Scale, volcanic ash, severe weather, extreme winds, and forced entry.  We refer to the shelters as nuclear blast proof, since that is the most extreme force that they will likely encounter.

The Vivos structure is hardened and reinforced with steel and concrete, as well as extensive bracing, seismic joints and shock absorbing materials to withstand this level of blast pressure, as well as up to 80 PSI of loading throughout the structure.  The entire Vivos internal and external structure is designed to bend and flex, disperse both overpressure loads and movement from lateral forces, absorbing the anticipated rolling, lateral, and severe shock forces, while maintaining its structural integrity.  By having a structure that is designed to move with lateral forces and move independently we allow the shock wave to move past us.  In a normal concrete blockhouse design the structure itself has to take the brunt of the force, instead of dissipating the force and allowing the structure to move as needed.  Being designed to move and dissipate a shock wave and not attempt to stop it is the only way a structure can survive. 

All hatches, vents, materials and devices that are exposed to the surface are ballistically hardened to maintain their structural integrity from extreme shock waves and blast forces. 

It would take an almost direct hit from a nuclear device to compromise one of these hardened complexes. With a sudden pole shift the tectonic plates are expected to move great distances in very short periods of time, requiring the structure to be able to take massive shock waves and abuse.

A complete list can be viewed at:

http://www.terravivos.com/secure/threatscenarios.htm