Inverted arch

An inverted arch is a civil engineering structure in the form of an inverted arch, inverted in comparison to the usual arch bridge.

Like the flying arch, the inverted arch is not used to support a load, as for a bridge, but rather to resist sideways, inwards loads. The conventional arch supports a vertical load downwards on the centre of the arch and translates this into forces both downwards and outwards at the base of the arch. In most cases, this sideways force is a nuisance and must be resisted by either strong foundations or a further 'bowstring' girder, in the form of a tied-arch bridge.