Vaults are structures that span in one direction only, such as arches or longitudinal cylinders, also known as barrel vaults. Vault spans begin at around 40m and can reach over 100m. Geometrica vaults have been used as sports facilities, transportation terminals, aircraft hangars and for environmental protection.
Geometrica vaults are generally reinforced with ribs every few meters. Some architectural vaults are continuous space frames developed to the desired geometry.
Vaults come in several cross sectional forms:
- Parabolic: These work best for the longest spans with heavy gravity loads such as snow, and moderate wind loads.
- Circular: Ideal for high wind loads.
- Acute: This geometry is designed to carry concentrated loads such as walkways or tripper cars, and to shed snow.
- Bent: This is selected when the footprint space is very constrained.
- Compound curve: Alternative to Bent when space is constrained.
The ribs themselves generally have a triangular cross-section, but for very long spans, or for large bending moments, the ribs may have a double depth for a rhombus cross-section. And, similar to flat space frames, the top chord may have an increased density relative to the webs of the ribs. The end of a vault may be closed with a vertical wall or a semi-dome.