1.1 This practice covers procedures, soils, and soil placement for the proper installation of corrugated aluminum structural plate culverts and sewers in either trench or embankment installations. A typical trench installation is shown in Fig. 1, and a typical embankment (projection) installation is shown in Fig. 2. Structural plate structures as described herein are those structures factory fabricated in plate form and bolted together on site to provide the required shape, size, and length of structure. This practice applies to structures designed in accordance with Practice B790/B790M.