Structural plate structures, sometimes referred to as sectional plate structures, have been used for many purposes. In general, structural plate pipe (SPP) or structural plate pipe-arch (SPPA) is used when the maximum size of CSP or CSPA is exceeded or where greater or differential thicknesses are required. Structural plate pipe and pipe-arch are available in a wide range of sizes. The minimum diameter of the pipe is 5 feet and the maximum is 26 feet. The minimum span x rise of the Pipe-Arch is 6 foot-1 inch x 4 foot-7 inch and the maximum is 20 foot-7 inch x 13 foot-2 inch. Structural plate structures are commonly used in flood control, drainage and sewer systems. They have also been used successfully for overhead conveyor covers and passages; vehicular, pedestrian, and animal underpasses; and storage bins. They have also proven to be sound and economical structures in many other applications.
Given equal end area, height of cover, or wherever otherwise applicable, the round shape is generally more economical and easier to assemble.