Arching

Arching refers to the act or result of forming an arch, a curved structural element that spans an opening and transfers load to its supports. In architecture and civil engineering, an arch channels compressive forces along its curve, creating a stable, self-supporting form. The design reduces bending moments compared with a flat beam, allowing spans to be covered with relatively light supports. Common arch shapes include semicircular arches, segmental arches with a shallow curve, and pointed arches associated with Gothic architecture. Other varieties include elliptical and parabolic arches, each with distinct load paths and aesthetic characteristics. Construction typically uses wedge-shaped voussoirs arranged around a central keystone, with abutments at each side to resist thrust.

In structural practice, arching also describes the distribution of forces within materials and across assemblies, influencing how arches resist loads such as gravity, wind, or seismic effects. The choice of shape, thickness, and curvature affects strength, span, and the amount of thrust transmitted to supporting elements. Materials commonly used for arches include stone, brick, concrete, and steel, with construction methods ranging from traditional voussoir arches to modern reinforced concrete and steel-frame solutions.

Arching appears in other contexts as well. In geology and soil mechanics, arching describes the redistribution of stress in soils, where load can be carried by a curved path through surrounding material, reducing pressure on retaining structures. In everyday language, arching denotes bending a part of the body into an arch, such as arching the back or the eyebrows.