Patent ID: 7063108

Claim:
A corrugated pipe having a longitudinal axis comprising: a plurality of corrugation structures positioned adjacent one another to form a portion of the corrugated pipe, the corrugation structures being centered on the longitudinal axis of the corrugated pipe, each corrugation structure comprising: a cylindrical wall centered on the longitudinal axis, the cylindrical wall having a radially outer edge; and an annular U-shaped wall extending from the cylindrical wall, the U-shaped wall comprising: two annular straight walls that are spaced from each other and that extend outwardly from the cylindrical wall, each straight wall having a radially outer end and a radially inner end; and a bowed wall extending axially between the radially outer ends of the two annular straight walls, wherein the shape of the annular U-shaped wall of each corrugation structure and the distance between adjacent corrugation structures are a function of a natural soil slip angle of a preselected backfill soil.