Arches

By Ryan Krause
arch (/ärCH/) N. A curved symmetrical structure spanning an opening and typically supporting the weight of a bridge, roof, or wall above it.



Examples:
external image stlouisarch_000.jpg
external image garch.jpgexternal image 300px-RomeConstantine'sArch03.jpgexternal image angeles-forest-arch-bridge.jpg



This is a short video on the basics of Arches



Arch History

The arch has been found in many different cultures, as early as Mesopotamia. The Egyptians used it in tombs and vaults but never for monumental architecture, such as temples. They apparently thought it unsuited to this purpose. The Greeks also used the arch solely for practical constructions, but many of the principles they developed were later exploited by the Romans.
Overall, it was not until the time of the Etruscans that the arch was used in any kind of monument. The best example of this is the Porta Augusta, where the arch is combined with Greek architectural ideas. The Romans borrowed this combination and used it over and over again, but its invention belongs solely to the Etruscans.

The Romans took many great strides in the development of the arch. While they borrowed many techniques from earlier races, the Romans invented the idea of setting an arch on top of two tall pedestals to span a walkway such as a public highway. The outer wall of the Colosseum appears composed almost completely of arches. Here we see examples of the barrel vault and the more complicated groined vault, both developed by the Romans from the basic arch. The Romans also used arches for common purposes, such as in the building of bridges and aqueducts.

Arches continued to be used in Medeival times, especially in cathedrals, where they helped support the great weight of the stone ceilings, especially when walls were weakened by the presence of many windows. It is here that buttresses were often used to support the arches. Sometimes called "flying buttresses" because of their height, buttresses are a simple construction of a stone pillar with a "bridge" at the top that joins onto the arch or walls of the building, giving extra support to the construction. Arches were also often found in long rows in cathedrals to help support each other. It is about this time that the pointed arch began to be developed, as an alternative to the traditional rounded arch. This pointed or Gothic arch became very prevalent in the architecture of the time.

Unique to architecture was the Islamic arch, found about the same time in the Middle East. Many advances were made in the arch by this culture as well. While the pointed arch was used here, the Muslims also developed a horseshoe-shaped arch and "stacked arches," an arch built above an arch. It is believed that the "stacked arch" idea developed by accident, when a builder was forced to use columns too short for his purpose and so stacked them on top of each other, with arches holding the stacked columns together. Islamic arches can be found in mosques throughout the Middle East.

Building Arches

Arches are constructed in steps. First, a scaffolding is placed as a frame, and allowed workers to stay safe at the top of the soon-to-be arch. Then, centering frames are placed, which form the inside of an arch. Stones are placed on these frames, and are cut to perfection to form the arch. The final stone, called the keystone, is placed last, at the very top of the arch. Once the keystone is placed, the centering frames and scaffolding can be removed as the weight is all distributed as shown in the video above. Finally, whatever is being placed on top of the arch can be added, such as rocks for an archway or a road for a bridge.

Arches Today

Since the Romans, we have also used arches in the same way to help us in our daily life. Without the arch, we wouldn't be able to cross canyons or valleys on bridges. Without the arch, we couldn't have arched doors or windows. Without the arch, We wouldn't have a monument such as the Gateway Arch in St. Louis.


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Comment japiekos japiekos 0 19 May 22, 2012 by japiekos japiekos
arches laheinson laheinson 0 21 May 22, 2012 by laheinson laheinson
Krista Craven kncraven kncraven 0 28 May 21, 2012 by kncraven kncraven
Stephanie Che sche2012 sche2012 0 10 May 17, 2012 by sche2012 sche2012
Miranda Ellis meellis1 meellis1 0 14 May 17, 2012 by meellis1 meellis1


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Citations:
http://oi.uchicago.edu/OI/MUS/ED/TRC/MESO/architecture.html
http://www.bbc.co.uk/history/british/launch_ani_build_arch.shtml
http://theriverlands.tripod.com/Writings/Arch/arch.html