Parabolic arch

[1] In structures, their curve represents an efficient method of load, and so can be found in bridges and in architecture in a variety of forms.

[4][5] Self-supporting catenary arches appeared occasionally in ancient architecture, for examples in the main arch of the partially ruined Sassanian palace Taq Kasra (now in Iraq), the largest single-span vault of unreinforced brickwork in the world, and the beehive huts of southwestern Ireland.

In the modern period, parabolic arches were first used extensively from the 1880s by the Catalan architect Antoni Gaudí,[6] deriving them from catenary arched shapes, constructed of brick or stone, and culminating in the catenary based design of the famous Sagrada Familia.

Since the 1990s Spanish designer Santiago Calatrava has frequently used parabolas for his signature roof structures and bridges.

Modern suspension bridges were built from the early 19th century, beginning with chains and progressing to more and more elegant steel rope examples, and are still in use today.