Ground and structure
Arch
bridgeportalsoportalaqueduct
It is a curved structure made of wedge-shaped pieces, called voussoirs, that spans an opening working in compression.
Solves
What it solves
It makes it possible to cover large openings with small pieces of stone or brick without a beam. It pushes outward, so it needs firm supports.
Today
Make sure the supports resist the lateral thrust with abutments, buttresses or a tie rod. In seismic zones the masonry arch is reinforced or combined with concrete or steel.
Common mistake
Using the arch as an ornament stuck onto a structure that neither needs it nor supports it.
Tomorrow
A well-drawn arch works only in compression and needs almost no steel. Building it with local brick or earth lowers carbon and keeps an ancient craft alive.
Where it comes from
- 1Mesopotamia Nippur, Iraq, before 3800 BC
One of the oldest known arches. - 2Etruscans and Romans Italy, since the 4th century BC
They used it in bridges, city gates and aqueducts. - 3Islamic world Jerusalem and Cairo, since the late 7th century
The first pointed arches appear, which centuries later passed to Gothic Europe. - 4Maya Mesoamerica, pre-Hispanic period
It used the corbel arch of stones projecting course by course, which does not work like a true arch.
Masters
- Louis Kahn Indian Institute of Management, Ahmedabad, India, 1974
He opens large arches in brick walls and ties their base with an exposed concrete beam. The beam takes the lateral thrust and the brick works only in compression.
See also
Also in Ground and structure
Diagrams and texts by LDB Arquitectura. They are shared under the CC BY 4.0 license, which allows them to be used and adapted with credit to the source.