Structure / Load-bearing element

Arch

/ɑːrtʃ/noun

From Latin arcus, meaning “bow” or “curve,” through Old French arche.

Definition

A curved structural element that spans an opening and supports the weight above it. An arch transfers loads through compression along its curve, directing them into the supporting piers or abutments on either side.

SPANKeystoneVoussoirsIntradosSpringing lineAbutmentExtrados
Fig. 13 — Arch: schematic studyNOT TO SCALE
Illustrative photograph of arch
Illustrative study — Arch · AI-generatedSAMPLE IMAGE
Visual study — the arch and its load path00:08

Structural & construction notes

In a traditional masonry arch, wedge-shaped blocks called voussoirs are arranged around the curve. The central keystone completes the ring. Temporary support, known as centering, holds the stones during construction until the arch is complete. The supports must resist both vertical loads and outward thrust.

An educational reference. Project-specific design requires professional guidance.