Engineering:Squinch

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In architecture, a squinch is a structural element used to support the base of a circular or octagonal dome that surmounts a square-plan chamber.[1] Squinches are placed to diagonally span each of the upper internal corners (vertices) where the walls meet. Constructed from masonry, they have several forms, including a graduated series of stepped arches; a hollow, open half-cone (like half of a funnel laid horizontally); or a small half-dome niche. They are designed to evenly spread the load of a dome across the intersecting walls on which it rests, thus avoiding concentrating higher structural stress on smaller load-bearing areas. By bridging corners, they also visually transition an angular space to a round or near-circular zone.[2]

Squinches originated in the Sassanid Empire of Ancient Persia, remaining in use across Central and West Asia into modern times. From its pre-Islamic origin, it developed into an influential structure for Islamic architecture.[3]Cite error: Closing </ref> missing for <ref> tag[4] After the rise of Islam, it remained a feature of Islamic architecture, especially in Iran, and was often covered by corbelled stalactite-like structures known as muqarnas. It was used in Western Asia and the Middle East, and in eastern Romanesque architecture, although pendentives are more common in Byzantine architecture. The Hagia Sophia features both squinches and pendentives, in combination.

Western Europe

Squinch in the Baptistery of San Giovanni in Fonte, Italy

The feature spread to the Romanesque architecture of western Europe. The earliest squinch still extant in Europe is the 5th-century Baptistery of San Giovanni in Fonte, Naples.[5] A later example is the 12th-century Norman church of San Cataldo, Palermo, in Sicily. This has three domes, each supported by four doubled squinches.

Etymology

The word may possibly originate, the Oxford English Dictionary suggests, from the French word escoinson, meaning "from an angle", which became the English word "scuncheon" and then "scunch".[6]

See also

References

  1. ↑ Webster's Ninth New Collegiate Dictionary, 1986, p. 1145
  2. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named cress
  3. ↑ Labisi, Giuseppe (2 July 2020). "Squinches and Semi-domes between the Late Sasanian and Early Islamic Periods". Iran 58 (2): 236–249. doi:10.1080/05786967.2019.1633241. 
  4. ↑ Golzari, Elaheh; Rabb, Péter (26 September 2022). "Revisiting the Geometry of the Transition Zone Using Filposh Squinches in Ardeshir Palace" (in en). Építés – Építészettudomány 50 (3-4): 351–364. doi:10.1556/096.2022.00079. ISSN 1588-2764. https://akjournals.com/view/journals/096/50/3-4/article-p351.xml. 
  5. ↑ Dalton, O. M. (1925). "The Penditive and Squinch". East Christian Art: A Survey of the Monuments (New York: Hacker Art Books; 1975 facsimile ed.). Oxford: Clarendon Press. pp. 85–87. [Ormonde Maddock Dalton]. https://archive.org/details/eastchristianart0000dalt/page/86/mode/2up. " ... the squinch was the earliest method employed in Armenia; and its appearance in a domed building over a square plan as far east as Chinese Turkestan (Turfan), which dates from the eighth century at latest, supports [the] ... contention that it is an indigenous Asiatic invention, employed from the first in the domed Iranian dwellinghouse, which is still erected in almost its primitive form to-day."  ISBN 978-0-87817-135-4.
  6. ↑

Further reading

Template:Islamic architecture



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