arch
Arch is one of the common building structures, the type is defined as the central half of the arc curve. Arch early often used in large span bridge or gate. Can be divided into box arch, arc arch, double arch, rib arch, truss arch, rigid arch and so on. In recent years, countries in the design of such as arch bridge, in addition to pay attention to safety and practical, but also stressed the arch axis optimization, arch calculation, arch structure load horizontal distribution, so that various forms of arch in the perfect building. The arch was the earliest brick building of Mesopotamia, which appeared in the year two thousand BC, but it was not until the time of the Roman period that the arch was systematically applied in many building structures. ^ Ancient Mesopotamia: Architecture. The Oriental Institute of the University of Chicago ..