Corbel#Corbelling

Corbelled, corbelled vault or wrong, a preform of the real vault is referred to as the top component of a room. In parallel, it has been around since the earliest times Kragkuppeln, Kragsteinkuppeln or false domes.

Structural Engineering

" Corbelled " or " domes " are based on the Kragbogen. Horizontal bricks form a cantilever, so fed pushed each other, an arc shape that tapers upwards to a conclusion usually larger stone without stabilizing function. This taper can be oblong or circular, depending on whether it is rectangular or round spaces. Unlike the real vault, like a bow itself stabilizes, a corbelled must be secured by vertical pressure on the outer sides of the voussoirs. Corbelled are therefore always steep and massive.

Examples

The German scholar Gerhard Rohlfs explored more than 30 years Rurale Kraggewölbebauten of dry masonry in Europe. In 1957 he published the results in the book Primitive domes in Europe.

The oldest surviving examples of buildings with corbelled offer the tholos chambers at the Cairn of Barnenez in Brittany (4500-4000 BC). How old is this type may be buildings in Western Europe, one recognizes the Cairn He - Mane at Carnac. The megaliths of Newgrange type in Ireland, Wales and Scotland are examples of this technique (about 3150 BC). In Irish and Scottish Souterrains the corbelled roof was partly used.

Corbelled dome graves found in Iberian (Los Millares ) and Sardinian giant tombs. The Maltese temples must have possessed roof structures Kraggewölben. The technique of building with corbels can also be found in the older Egyptian pyramids, for example, in the Bent Pyramid of Pharaoh Sneferu (ca. 2500 BC ) and in the Grand Gallery of the Great Pyramid of Cheops in dome tombs on Crete or in Treasury of Atreus, which was built in the 14th century BC at Mycenae. Even older Cypriot tholoi of Chirokitia could be that have not been preserved. The navetas the Balearic and Sardinian Nuraghe (ca. 1800-500 BC ), the last culture-forming systems in which the Kraggewölbetechnik was used ( in part ) with megaliths.

The corbelled is also a typical element of style of Maya architecture and an example of a stretched (ie rectangular ) "false arches ." The inner wall of the " vault " was often made ​​up of almost uncut long stones or stone slabs that were plastered on the inside; only in the classical period (ca. 600-900 AD), the stones of the false vault in some cases ( Uxmal, Kabah, Labná ) were trimmed smooth. By filling with gravel by the weight force acts on the rear part of the coping, whereby the latter are held in position. This allowed the Maya " vault " to a maximum of about 6 meters build width and any length. This has been bought, that the ceilings of the rooms and the steep roof structures were very heavy and very high. Other cultures of Mesoamerica did not know such constructions and on the entire American continent was the principle of "real vault " until the arrival of Europeans unknown.

The pre-Islamic Architecture Asia knows no real arch or dome; the temples of India or behind Indian architecture are preferably flat ceilings. Only the pyramid roofs and towers Shikhara some Indian temple ( Naresar ) show the gradual emergence of stone Kragkonstruktionen, but not initially were visible inside the temple. It was not until relatively late ( around the age of 7 / 8 th century ) were in India and other regions of South Asia ( Angkor ) "false arch " or "false domes " in Kragtechnik in the interior of the buildings visible. How long is the Hindu craftsmen - even under Islamic rule - clung to the traditional corbelled roof, show the portal arches and the Kragsteinkuppel the entrance of the Quwwat -ul -Islam Mosque in the Qutb complex in Delhi. Some Kragsteinkuppeln in later Hindu (Khajuraho ) or Jain temples (Mount Abu, Ranakpur ) are among the most unsurpassed masterpieces of their kind

Pictures

Corbelled a chamber of the Red Pyramid of Dahshur, Egypt ( 2650 BC)

Corbelled in an old farmhouse in Gozo - the horizontal keystones are supported by wooden beams

Kragkuppel in Arrubiu Nuraghe, Sardinia (around 1500 BC)

Maya Vault inside the temple of the seven dolls in Dzibilchaltún ( AD 600 to AD)

Intrados of a Mayan arch in Uxmal, Yucatan ( 800 )

Sham dome over the entrance to Quwwat -ul -Islam mosque in Delhi ( 1200 )

Mount Abu (Rajasthan), Kragsteinkuppel in the Dilwara temples (13th century)

Ranakpur (Rajasthan), Kragkuppel in Adinath Temple ( 15th century)