Arch
An arch is an opening in a building that is curved on top to distribute the weight. The curved part can be round, like part of a circle, or pointed, like two parts of circles next to each other. Arches are often used where buildings are made of many small stones or bricks. The stone at the very top of the arch, called the keystone, keeps the rest of the arch stones from falling down. Arches can go over doorways and windows. Many bridges are arch bridges including ones made of steel. A series of arches is an arcade.
Arches can be found in nature. These natural arches form through the erosion of cliffs.[1]
Types of arches
Arches can have many forms, but they can be sorted into three categories: circular, pointed and parabolic.
- Circular (rounded) arches were used by Romans. They used them in bridges, aqueducts, and large-scale (big) architecture.[2]
- Pointed arches were most often used by builders of Gothic-style architecture. They used them because they produced less thrust at the base. This allowed the structures to be taller.[3]
- Parabolic arches have the shape of a parabola. They are mostly used in bridges.
- Ogee arches features an S-shaped curve, typically used in Islamic architecture and Gothic Revival styles.
- Horse Shoe arches often used in Moorish and Islamic architecture, is characterized by shapes that are more curved than semi-circles.
Arch Media
The Gateway Arch, part of the Jefferson National Expansion Memorial in St. Louis, Missouri, framing the courthouse where the Dred Scott decision was read.
Arch: Schematic illustration of an arch.*Note: This is a general representation of the proportions and technical elements. * Keystone * Voussoir * Back * Impost * Intrados * Rise * Clear span, "Bay" * Abutment
Arch (A) action diagram in comparison with a beam (B)
Types of arches from Sturgis' Illustrated Dictionary of Architecture and Building
Pointed arches, 1 - equilateral with trefoil treatment, 2 - blunt, 3 - lancet, 4 - ogee, 5 - four-centred, 6 - curtain (inflexed), 7 - pointed horseshoe
Rossgraben bridge (Rüeggisberg) near Bern, Switzerland, showing the hinge at mid-span of this three-hinged arch.
A series of parabolic arches on the Móra d'Ebre bridge, Catalonia, Spain (2005)
Analogy between an arch and a hanging chain and comparison to the dome of Saint Peter's Basilica in Rome (Giovanni Poleni, 1748)
A complex funicular model (Church of Colònia Güell by Gaudi, 19th century)
Arcades of Pont du Gard (Roman)
.jpg)
.jpg)
Sources
- ↑ McDade, Arthur (2000). The Natural Arches of the Big South Fork: A Guide to Selected Landforms. Univ. of Tennessee Press. ISBN 9781572330740.
- ↑ "Arch | architecture". Encyclopedia Britannica. Retrieved 2019-02-08.
- ↑ "What We Can Learn From the Exquisite History and Ornate Aesthetic of Gothic Architecture". My Modern Met. 2017-11-14. Archived from the original on 2019-04-17. Retrieved 2019-02-08.
Other websites
Media related to Arch at Wikimedia Commons
