Ramping arch

The ramping arch (also known as rampant arch, from French: arc rampant, and raking arch) is an asymmetrical arch that has its springers located at substantially different heights. Frequently a ramping arch is associated with a ramp or stairs.

Originally used to support inclined structures, like stairs or ramps, in the 13th-14th centuries the rampant arch appeared as parts of flying buttresses used to counteract the thrust of Gothic ribbed vaults, typical design was based on a truncated semicircular arch. Viollet-le-Duc in 1854 described two arch types in buttresses: the earlier one where the center of the intrados segment is located on the face of the wall (intrados close to a quarter-circle), and the later, more efficient, design where the center is moved inside the wall, narrowing the segment. The main purpose of a buttress is to relay the thrust to the foundations, the structure also accommodates the downspouts. A typical flying buttress used a single-arch arrangement, although two-tiered arches and even three-tiered designs were used.

The ramping arches can consist of a single circle segment (typical for flying buttresses of large cathedrals) or from two segments with different centers and radii connected at the keystone.