Arc elevation

Architecture

Arch, in architecture and civil engineering, a curved member that is used to span an opening and to support loads from above. The arch formed the basis for the evolution of the vault. Arch construction depends essentially on the wedge. If a series of wedge-shaped blocks—i.e., ones in which the upper edge is wider than the lower edge—are set flank to flank in the manner shown in the figure, the result is an arch. These blocks are called voussoirs. Each voussoir must be precisely cut so that it presses firmly against the surface of neighbouring blocks and conducts loads uniformly. The central voussoir is called the keystone. The point from which the arch rises from its vertical supports is known as the spring, or springing line. During construction of an arch, the voussoirs require support from below until the keystone has been set in place; this support usually takes the form of temporary wooden centring. The curve in an arch may be semicircular, segmental (consisting of less than one-half of a circle), or pointed (two intersecting arcs of a circle); noncircular curves can also be used successfully.

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Arc , architecture , architectural , elements , gate , passage , door , way , arabic , middle , east , gulf , arab , decoration , decorative