Definition

Noun: - A structural architectural element: A "flat arch" is an arch constructed with wedge-shaped stones or bricks (voussoirs) that support each other. Its defining characteristic is that both its outer curve (extrados) and inner curve (intrados) are straight and horizontal, giving it a flat appearance despite functioning as an arch.

Usage

• Architectural and Construction Context: This term is used specifically in architecture, engineering, and construction to describe a type of arch design.
  • The builder chose a flat arch for the opening to maintain a clean, modern line.
  • Despite its name, a flat arch is a true arch that distributes weight through its voussoirs.

Advanced Usage

• Technical Description: In technical specifications, a "flat arch" is distinguished from a "jack arch" or "segmental arch" by its precisely horizontal intrados and extrados.
  • The structural calculations for a flat arch differ from those for a semicircular arch.

Variants and Related Words

• Jack Arch: Often used synonymously, though some definitions specify a jack arch has a slightly curved intrados.
• Voussoir (n): A wedge-shaped stone or brick forming one of the units of an arch.
• Extrados (n): The outer curve of an arch.
• Intrados (n): The inner curve or underside of an arch.

Synonyms

• Straight arch: A less common synonym emphasizing the horizontal line.
• French arch: An alternative name used in some regions.

Related Phrases

• To build/support a flat arch: Refers to the construction method.
  • The mason knew how to properly support a flat arch during construction.

Noun

1. an arch with mutually supporting voussoirs that has a straight horizontal extrados and intrados