Arch

Basic Concepts and History of Arches: An arch is a curved vertical structure used for support or decoration. Arches have been utilized since the fourth millennium BC. They can be horizontal, like arch dams, and are often used as supports for vaults. Terminology and Components of Arches: A true arch is loadbearing and held together by compression. Components of a masonry arch include keystone, voussoir, and extrados. Terms like false arch, intrados, and archivolt are essential in understanding arch structures. Arch Action and Construction Techniques: A true arch resolves vertical loads into horizontal and vertical reactions. Modern arch construction uses ties to relieve horizontal thrust. Counterarches were traditionally used to counteract horizontal forces. New construction materials have made arches lighter and less reliant on heavy abutments. Shapes and Classifications of Arches: Arches can be classified by their intrados shape, number of circle segments, and construction material. Shapes of arches can be rounded, pointed, or parabolic. Classification includes brick arches, stone arches, and structural classifications based on movable joints. Specific Arch Shapes and Examples: Rounded arches include semicircular, segmental, baskethandle, and horseshoe arches. Pointed arches consist of two or more circle segments culminating in a point. Examples of arch shapes are found in various architectural styles like Roman, Islamic, and Gothic.