1.1 ,This practice is intended for the structural design of corrugated aluminum pipe and pipe-arches, and aluminum structural plate pipe, pipe-arches, and arches for use as culverts and storm sewers and other buried conduits. This practice is for pipe installed in a trench or embankment and subjected to highway, railroad, and aircraft loadings. It must be recognized that a buried corrugated aluminum pipe is a composite structure made up of the aluminum ring and the soil envelope, and both elements play a vital part in the structural design of this type of structure.