Final answer:
When two barrel vaults intersect at right angles, a groin vault is created. This architectural element allows for significant design flexibility in the space beneath due to its corner-supported structure. Barrel vaults have historically been important in constructing various types of spaces, from darker Romanesque churches to aqueducts and basilicas.
Step-by-step explanation:
When two barrel vaults intersect at right angles, a groin vault is created. Groin vaults are characterized by their distinct x-shape, visible when viewed from the ceiling of the vault. This architectural feature concentrates the thrust along the x-pattern formed at the intersection, allowing for the weight to be supported mainly at the corners. As such, groin vaults enable architects and engineers to have more flexibility in designing the space beneath them, providing the ability to incorporate various elements without the constraints of continuous lateral support.
The barrel vault itself is a simple yet effective structural form, comprising a series of arches placed in succession to form a tunnel-like shape. This method has been historically significant, notably in Romanesque churches, which utilized barrel-vault construction to enhance acoustics, decrease fire risk, but also resulted in darker interiors due to the thick walls needed to counteract the vault's lateral thrust.
These principles are not only applied to vaults but also to larger structures such as domes, which have been constructed by rotating an arch around a single point. Innovative uses of the barrel vault are seen in various constructions, such as Roman aqueducts and public basilicas, which exemplify the versatility and importance of this architectural form.