Segmental arch
A segmental arch is a type of arch with a circular arc of less than 180 degrees.[1] It is sometimes also called a scheme arch.[2]
The segmental arch is one of the strongest arches because it is able to resist thrust.[3] To prevent failure, a segmental arch must have a rise[lower-alpha 1] that is equal to at least one-eighth the width of the span. Segmental arches with a rise that is less than one-eighth of the span width must have a permanent support or frame beneath the arch to prevent failure.[3]
As far as is known, the ancient Romans were the first to develop the segmental arch. The closed-spandrel Pont-Saint-Martin bridge in the Aosta Valley in Italy dates to 25 BC.[5] The first open-spandrel segmental arch bridge is the Anji Bridge over the Xiao River in Hebei Province in China, which was built in 610 AD.[6]
Segmental arches are most commonly used in the 20th century in residential construction over doorways, fireplaces, and windows.[3]
References
- Notes
- Citations
- Harris, Cyril M. (1983). Illustrated Dictionary of Historic Architecture. New York: Dover Publications. p. 485. ISBN 9780486244440.
- Smith, Percy Major (2015). Rivington's Building Construction. Abingdon, Oxfordshire, U.K.: Routledge. p. 6. ISBN 9781317742432.
- Kreh, Richard T. (2015). Masonry Skills. Stamford, Conn.: Cengage Learning. p. 401. ISBN 9781285426839.
- Auslander, Alfred (June 1910). "Lessons in Architectural Drawing for Beginners". The Building Age. p. 241. Retrieved June 4, 2017.
- O'Connor, Colin (1993). Roman Bridges. Cambridge, U.K.: Cambridge University Press. p. 171. ISBN 9780521393263.
- Temple, Robert K.G. (1986). China: Land of Discovery. Wellingborough, Northamptonshire, U.K.: Stephens. pp. 69–71. ISBN 9780850598582.