A masonry arch
1.  Keystone 2.  Voussoir 3.  Extrados 4.  Impost 5.  Intrados 6.  Rise 7.  Clear span 8.  Abutment

An arch is a structure capable of spanning a space while supporting significant weight (e. Span is a section between two intermediate supports eg of a beam or a Bridge. g. a doorway in a stone wall). A wall is a usually solid structure that defines and sometimes protects an area True arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture and in Persian ziggurats (see Chogha Zanbil). Mesopotamia (from the Greek meaning "land between the rivers" is an area geographically located between the Tigris and Euphrates rivers largely corresponding Chogha Zanbil (چُغازَنبیل is an ancient Elamite complex in the Khuzestan province of Iran. True arches were also built by the Babylonians in the 6th century BC (see Ishtar Gate ). Babylonia was an Amorite state in lower Mesopotamia (modern southern Iraq) with Babylon as its capital The Ishtar Gate ( Assyrian: ܕܵܪܘܲܐܙܲܐ ܕܥܵܐܫܬܲܪ translit Darwaza D'Ishtar, Arabic:بوابة عشتار was the The arch then spread to Europe and was adopted by the Ancient Greeks, Etruscans, and Ancient Romans. The term ancient Greece refers to the period of Greek history lasting from the Greek Dark Ages ca Etruscan civilization is the modern English name given to the culture and way of life of a people of ancient Italy Ancient Rome was a Civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC The arch became an important technique in medieval European cathedral building as well as Islamic architecture. This article is about the history and organisation of the cathedral Across the ocean in Mexico and Central America, Mesoamerican civilizations created various types of corbelled arches, such as with the interior tunnels in the Great Pyramid of Cholula and the many styles of corbelled arches built by the Mayan civilization. Mesoamerica or Meso-America (Mesoamérica is a Region extending approximately from central Mexico to Honduras and Nicaragua, defined Use in historical cultures Maya civilization MykeneTreasureof The Great Pyramid of Cholula or Tlachihualtepetl ( Nahuatl for "artificial mountain" is a huge complex located in Cholula, Puebla, In Peru, the Inca civilization used a trapezoidal arch in their architecture. The arch is still used today in some modern structures such as bridges. A bridge is a Structure built to span a Gorge, Valley, Road, railroad track, River, Body of water

History

Roman bridge in Alcántara, Spain

Arch of the General Staff Building in Palace Square, St Petersburg

The incomplete mausoleum of Adil Shah, Barakaman (Ali Roza-II), which means twelve arches in Urdu

Arches were first created and used by the Mesopotamian, Persian, Harappan, Egyptian, Babylonian, and Assyrian civilizations. For a list of all known Roman bridges see List of Roman bridges For the railway station in Wales, see Roman Bridge railway station Alcántara is a municipality (pop 1769 in the province of Cáceres, Extremadura, Spain, on the Tagus, near Portugal. Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. Palace Square or Dvortsovaya Ploshchad, connecting Nevsky Prospekt with Palace Bridge leading to Vasilievsky Island, is the central City Saint Petersburg ( tr: Sankt-Peterburg,) is a city and a federal subject of Russia located on the Neva River Urdu ( ur '''{{Nastaliq اردو}}''' trans Urdū, historically spelled Ordu) is a Central Indo-Aryan language Urdu is a standardised Mesopotamia (from the Greek meaning "land between the rivers" is an area geographically located between the Tigris and Euphrates rivers largely corresponding The Persian Empire was a series of Iranian empires that ruled over the Iranian plateau, the original Persian homeland and beyond in Western Asia Harappan architecture is the Architecture of the Harappans an ancient people who lived in the Indus Valley from about 3300 BCE to 1600 BCE Ancient Egypt was an Ancient Civilization in eastern North Africa, concentrated along the lower reaches of the Nile River in what is now Babylon was a City-state of ancient Mesopotamia, the remains of which can be found in present-day Al Hillah, Babil Province, Iraq Early history The most Neolithic site in Assyria is at Tell Hassuna, the center of the Hassuna culture Many arches were used in buildings and in monumental architecture, such as in the Ishtar Gate and the ziggurat of Chogha Zanbil. The Ishtar Gate ( Assyrian: ܕܵܪܘܲܐܙܲܐ ܕܥܵܐܫܬܲܪ translit Darwaza D'Ishtar, Arabic:بوابة عشتار was the Chogha Zanbil (چُغازَنبیل is an ancient Elamite complex in the Khuzestan province of Iran. Other arches were used in underground structures such as drains where the problem of lateral thrust is greatly diminished.

From the Middle East, knowledge of arch building spread to Europe. The Middle East is a Subcontinent with no clear boundaries often used as a synonym to Near East, in opposition to Far East. The ancient Romans learned the arch from the Etruscans (who originally migrated out of the Middle East), refined it and employed it for above ground buildings. The Architecture of Ancient Rome adopted the external Greek architecture for their own purposes which were so different from Greek buildings as to create a new Etruscan civilization is the modern English name given to the culture and way of life of a people of ancient Italy Throughout the Roman empire, their engineers erected arch structures such as bridges, aqueducts, and gates. The Roman Empire was the post-Republican phase of the ancient Roman civilization, characterised by an autocratic form of government and large territorial For a list of all known Roman bridges see List of Roman bridges For the railway station in Wales, see Roman Bridge railway station The ancient Romans constructed numerous aqueducts ( Latin aquaeductūs, sing They also introduced the triumphal arch as a military monument. A triumphal arch is a structure in the shape of a monumental Archway, in theory built to celebrate a victory in war actually used to celebrate a ruler Vaults began to be used for roofing large interior spaces such as halls and temples, a function which was also assumed by domed structures from the 1st century BC onwards. A dome is a common structural element of Architecture that resembles the hollow upper half of a Sphere.

The Roman arch is semicircular, and built from an odd number of arch bricks (called voussoirs). A voussoir is a wedge-shaped element typically a stone used in building an Arch. An odd number of bricks is required for there to be a capstone or keystone, the topmost stone in the arch. A keystone is the architectural piece at the crown of a vault or Arch and marks its apex, locking the other pieces into position The Roman arch's shape is the simplest to build, but not the strongest. There is a tendency for the sides to bulge outwards, which must be counteracted by an added weight of masonry to push them inwards. Masonry is the building of structures from individual units laid in and bound together by mortar, and the term "masonry" can also refer to the units themselves The Romans used this type of semicircular arch freely in many of their secular structures such as aqueducts, palaces and amphitheaters.

The semicircular arch was followed in Europe by the pointed Gothic arch or ogive (derived from the Islamic pointed arch in Moorish Spain), whose centreline more closely followed the forces of compression and which was therefore stronger. See also Gothic art Gothic architecture is a style of Architecture which flourished during the high and late medieval period. An ogive ("Oh-jive" is a curved shape figure or feature Al-Andalus (الأندلس was the Arabic name given to those parts of the Iberian Peninsula governed by Muslims or The semicircular arch can be flattened to make an elliptical arch as in the Ponte Santa Trinita. In Mathematics, an ellipse (from the Greek ἔλλειψις literally absence) is a Conic section, the locus of points in a The Ponte Santa Trinita ( Italian for Holy Trinity Bridge, named for the ancient church in the nearest stretch of via Tornabuoni is a Renaissance bridge The parabolic and catenary arches are now known to be the theoretically strongest forms. In Mathematics, the parabola (pəˈræbələ from the Greek παραβολή) is a Conic section, the intersection of a right circular In Physics and Geometry, the catenary is the theoretical Shape of a hanging flexible Chain or Cable when supported at its ends and Parabolic arches were introduced in construction by the Spanish architect Antoni Gaudí, who admired the structural system of Gothic style, but for the buttresses, which he termed “architectural crutches”. Spanish architecture refers to Architecture carried out in any area in what is now modern-day Spain, and by Spanish architects worldwide See also Gothic art Gothic architecture is a style of Architecture which flourished during the high and late medieval period. Crutches are Medical Tools used when a patient is injured usually anywhere below the waist The catenary and parabolic arches carry all horizontal thrust to the foundation and so do not need additional elements.

The horseshoe arch is based on the semicircular arch, but its lower ends are extended further round the circle until they start to converge. The first examples known are carved into rock in India in the first century AD, while the first known built horseshoe arches are known from Aksum (modern day Ethiopia and Eritrea) from around the 3rd–4th century, around the same time as the earliest contemporary examples in Syria, suggesting either an Aksumite or Syrian origin for the type of arch. The Aksumite Empire or Axumite Empire (sometimes called the Kingdom of Aksum or Axum ( Ge'ez: አክሱም was an important trading NOTE This intro is the result of careful NPOV work Please do not make potentially controversial edits to it without first discussing on the talk page Eritrea () ( Ge'ez: ኤርትራ ʾErtrā, Arabic: إرتريا Iritriya) officially the State of Eritrea, is a country in Syria ( سوريّة or) officially the Syrian Arab Republic (Arabic ar الجمهورية العربية السورية ^[1] It was used in Spanish Visigothic architecture, Islamic architecture and mudéjar architecture, as in the Great Mosque of Damascus and in later Moorish buildings. Islamic architecture has encompassed a wide range of both secular and religious styles from the foundation of Islam to the present day influencing the design and construction Mudéjar is the name given to the Moors or Muslims of Al-Andalus, who remained in Christian territory after the Reconquista but were A "mosque" in English refers to all types of buildings dedicated for Islamic worship although there is a distinction in Arabic between the smaller privately owned mosque and the larger Damascus ( دمشق,, also commonly known as الشام ash-Shām) is the capital and largest city of Syria. The description Moors has referred to several historic and modern populations of Muslim (and earlier non-Muslim people of Berber and Arab descent It was used for decoration rather than for strength.

In Mexico and Central America, Mesoamerican civilizations created various types of corbelled arches, such as with the interior tunnels in the Great Pyramid of Cholula and the many styles of corbelled arches built by the Mayan civilization. Mesoamerica or Meso-America (Mesoamérica is a Region extending approximately from central Mexico to Honduras and Nicaragua, defined Use in historical cultures Maya civilization MykeneTreasureof The Great Pyramid of Cholula or Tlachihualtepetl ( Nahuatl for "artificial mountain" is a huge complex located in Cholula, Puebla,

Construction

Isometric view of a typical arch

An arch requires all of its elements to hold it together, raising the question of how an arch is constructed. Isometric projection is a form of Graphical projection —more specifically an Axonometric projection. One answer is to build a frame (historically, of wood) which exactly follows the form of the underside of the arch. This is known as a centre or centring. Centring (UK or centering (US is the structure upon which the stones of Arches or vault are laid during construction The voussoirs are laid on it until the arch is complete and self-supporting. A voussoir is a wedge-shaped element typically a stone used in building an Arch. For an arch higher than head height, scaffolding would in any case be required by the builders, so the scaffolding can be combined with the arch support. Occasionally arches would fall down when the frame was removed if construction or planning had been incorrect. (The A85 bridge at Dalmally, Scotland suffered this fate on its first attempt, in the 1940s). The A85 is a major Road in Scotland. It runs east from Oban along the south bank of Loch Etive, through Lochawe and Tyndrum The interior and lower line or curve of an arch is known as the intrados.

Old arches sometimes need reinforcement due to decay of the keystones, known as bald arch. Bald arch is a technical term used by Engineers to describe the decay of the crucial Key stones in Medieval buildings particularly churches and Cathedrals

The gallery shows arch forms displayed in roughly the order in which they were developed.

Triangular arch	Round arch or Semi-circular arch	Segmental arch	Unequal round arch or Rampant round arch
Lancet arch	Equilateral pointed arch	Shouldered flat arch -see also jack arch	Three-foiled cusped arch
Horseshoe arch	Three-centered arch	Elliptical arch	Inflexed arch
Ogee arch	Reverse ogee arch	Tudor arch	Catenary or Parabolic arch

Technical aspects

When made from stone this becomes a true arch bridge, requiring stone approaches for structural stability. A jack arch is a structural element in Masonry construction that provides support at openings in the masonry Ogee is a shape consisting of a concave arc flowing into a convex arc so forming an S-shaped curve with vertical ends Ogee is a shape consisting of a concave arc flowing into a convex arc so forming an S-shaped curve with vertical ends Tudor arch, a low wide Arch, was a common architectural element in the Tudor period in England. In Physics and Geometry, the catenary is the theoretical Shape of a hanging flexible Chain or Cable when supported at its ends and In Mathematics, the parabola (pəˈræbələ from the Greek παραβολή) is a Conic section, the intersection of a right circular Chinese moon bridge

The arch is significant because, in theory at least, it provides a structure which eliminates tensile stresses in spanning an open space. Stress is a measure of the average amount of Force exerted per unit Area. All the forces are resolved into compressive stresses. Compressive stress is the stress applied to materials resulting in their compaction (decrease of volume This is useful because several of the available building materials such as stone, cast iron and concrete can strongly resist compression but are very weak when tension, shear or torsional stress is applied to them. In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Cast iron usually refers to grey cast iron, but identifies a large group of Ferrous Alloys which solidify with a Eutectic. Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag Stress is a measure of the average amount of Force exerted per unit Area. A shear stress, denoted \tau\ ( Tau) is defined as a stress which is applied Parallel or tangential to a face of a material The term torsion may refer the following In geometry Torsion of curves Torsion tensor in differential geometry By using the arch configuration, significant spans can be achieved. This is because all the compressive forces hold it together in a state of equilibrium. This even applies to frictionless surfaces. However, one downside is that an arch pushes outward at the base, and this needs to be restrained in some way, either with heavy sides and friction or angled cuts into bedrock or similar.

This same principle holds when the force acting on the arch is not vertical such as in spanning a doorway, but horizontal, such as in arched retaining walls or dams. In Physics, a force is whatever can cause an object with Mass to Accelerate. A retaining wall is a structure that holds back Soil or rock from a Building, structure or area A dam is a barrier that divides waters. Dams generally serve the primary purpose of retaining water while other structures such as Floodgates, Levees

Even when using concrete, where the structure may be monolithic, the principle of the arch is used so as to benefit from the concrete's strength in resisting compressive stress. Where any other form of stress is raised, it has to be resisted by carefully placed reinforcement rods or fibres. A rebar, or reinforcing bar, is a common Steel bar and is commonly used in Reinforced concrete and reinforced Masonry structures (See Arch bridge. )

Other types

The Delicate Arch, a natural arch

The Arc de Triomphe, Paris; a 19th century triumphal arch modeled on the classical Roman design. Delicate Arch is a tall freestanding Natural arch located in Arches National Park near Moab, Utah. The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar Ancient Rome was a Civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC

A blind arch is an arch infilled with solid construction so it cannot function as a window, door, or passageway. blind arch is an Arch found in the Wall of a Building which has been Infilled with solid construction so it cannot serve as a passageway

A dome is a three-dimensional application of the arch, rotated about the center axis. A dome is a common structural element of Architecture that resembles the hollow upper half of a Sphere. Igloos are notable early structures making use of domes. An igloo ( Inuit language: iglu, Inuktitut syllabics: ᐃᒡᓗ "house" plural iglooit or igluit, but in English

Natural rock formations may also be referred to as arches. These natural arches are formed by erosion rather than being carved or constructed by man. "Natural Bridges" redirects here for the US National Monument see Natural Bridges National Monument. Erosion is the carrying away or displacement of solids ( Sediment, Soil, rock and other particles usually by the agents of currents such as wind See Arches National Park for examples. Arches National Park is a US National park in southern Utah. It is known for preserving over 2000 natural sandstone arches, including the

A special form of the arch is the triumphal arch, usually built to celebrate a victory in war. A triumphal arch is a structure in the shape of a monumental Archway, in theory built to celebrate a victory in war actually used to celebrate a ruler A famous example is the Arc de Triomphe in Paris, France. The Arc de Triomphe is a monument in Paris, France that stands in the centre of the Place Charles de Gaulle also known as the Place de l'Étoile. Paris (ˈpærɨs in English; in French) is the Capital of France and the country's largest city This article is about the country For a topic outline on this subject see List of basic France topics.

A vault is an application of the arch extended horizontally in two dimensions; the groin vault is the intersection of two vaults. A Vault (French voute Italian volta German Gewölbe Polish sklepienie, Spanish A groin vault or groined vault (also sometimes known as a double barrel vault or cross vault) is produced by the intersection at

Gallery

The dry stone bridge, so called Porta Rosa (4th century BC), in Elea	Arch of Constantine, Rome, Italy commemorating a victory by Constantine I in 312 AD	The Gateway Arch in Saint Louis, Missouri; a sculpture based on a catenary arch	Doubled round archivolts - Igreja de Nossa Senhora da Assunção, Linhares da Beira, Portugal. Dry stone is a building method by which structures are constructed from stones without any mortar to bind them together "Velia" redirects here See also Velia (hill and Novi Velia. The Arch of Constantine (Italian Arco di Costantino is a Triumphal arch in Rome, situated between the Colosseum and the Palatine Hill. Rome ( Roma ˈroma Roma is the capital city of Italy and Lazio, and is Italy's largest and most populous city with more than 2 Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest Flavius Valerius Aurelius Constantinus (27 February ca. 272 &ndash 22 May 337 commonly known as Constantine I, Constantine the Great, or Saint Constantine The Jefferson National Expansion Memorial is located in St Louis Missouri near In Physics and Geometry, the catenary is the theoretical Shape of a hanging flexible Chain or Cable when supported at its ends and An archivolt is is an ornamental molding or band following the curve of the underside of an arch
Stonework arches seen in a ruined stonework building - Burg Lippspringe, Germany	Several arches at the Casa Simón Bolívar in Havana, Cuba	Arches in the Armenian monastery of Geghard. Bad Lippspringe is a town in the district of Paderborn, in North Rhine-Westphalia, Germany. Havana ( IPA: aˈβana officially Ciudad de La Habana, is the Capital city, major port and leading For the town see Geghard Armenia. The Monastery of Geghard ("Գեղարդ" in Armenian) is a unique architectural construction in

References

1. ^ Stuart Munro-Hay, Aksum: A Civilization of Late Antiquity. Edinburgh: University Press. 1991. ISBN 0-7486-0106-6, p. 111.

• Roth, Leland M (1993). Understanding Architecture: Its Elements History and Meaning. Oxford, UK: Westview Press. ISBN 0-06-430158-3.   pp. 27-8

See also

• Corbelled arch
• Blind arch
• Suspension bridge
• Triumphal arch
• Natural arch

External links

• Oldest Known Arch In The World Photography by a U. Use in historical cultures Maya civilization MykeneTreasureof blind arch is an Arch found in the Wall of a Building which has been Infilled with solid construction so it cannot serve as a passageway This article is concerned with a particular type of suspension bridge the suspended-deck type A triumphal arch is a structure in the shape of a monumental Archway, in theory built to celebrate a victory in war actually used to celebrate a ruler "Natural Bridges" redirects here for the US National Monument see Natural Bridges National Monument. S. soldier serving in Iraq.
• DIYinfo.org's Constructing Brick Arches Wiki - A wiki on how to construct brick arches around the house
• DIYinfo.org's Constructing Timber Framed Arches Wiki - Similar to the brick arches but extra information for timber arches