What part of an air seal burial vault entraps air and supports the weight of the earth above?

The dome of an air seal burial vault is specifically designed to entrap air and support the weight of the earth above it. The architecture of the dome allows it to distribute the weight more effectively than flat structures, thereby providing both structural integrity and the ability to create an air seal. The curvature and shape of the dome enable it to withstand external pressure, making it efficient in resisting soil loads and environmental forces.

Additionally, the air trapped within the dome aids in preserving the contents of the vault, as it helps create a controlled environment, reducing the chances of water and soil intrusion. This design is vital for the longevity and protection of the burial vault's contents, emphasizing the dome's critical role in fulfilling both functional and protective requirements.