Editing Arch (section)

== Classifications ==
There are multiple ways to classify arches:{{sfn | Punmia | Jain | Jain | 2005 | p=425}}
# [[#Shapes|by the geometrical shape]] of its intrados (for example, [[Semicircular arch|semicircular]], [[Triangular arch|triangular]], etc.);{{sfn | Punmia | Jain | Jain | 2005 | p=425}}<ref name=treccani>{{treccani|arco_(Enciclopedia-Italiana)|Arco||1929}}</ref>
# for the arches with rounded intrados, by the number of circle segments forming the arch (for example, [[round arch]] is single-centred, [[pointed arch]] is two-centred);{{sfn | Punmia | Jain | Jain | 2005 | p=425}}
# [[#Construction|by the material used]] (stone, brick, concrete, steel) and construction approach.{{sfn | Punmia | Jain |Jain | 2005 | p=425}} For example, the wedge-shaped voussoirs of a brick arch can be made by cutting the regular bricks ("axed brick" arch) or manufactured in the wedge shape ("gauged brick" arch);{{sfn | Punmia | Jain | Jain | 2005 | pp=431-432}}
# [[Structural analysis|structurally]], [[#Hinged arches|by the number of ''hinges'']] (movable joints) between solid components. For example, voussoirs in a stone arch should not move, so these arches usually have no hinges (are "fixed"). Permitting some movement in a large structure allows to alleviate stresses (caused, for example, by the [[thermal expansion]]), so many bridge spans are built with three hinges (one at each support and one at the crown) since the mid-19th century.{{sfn|Slivnik|2013|p=1089}}