The minimum soil cover requirements are provided for corrugated plastic pipe (high density polyethylene) to safely withstand vehicular loading when the pipe is installed under roadways such as in culvert applications. Pipe diameters ranging from 12 to 36 in. And all pipe wall corrugations currently produced are also included. Design criteria are adopted from aashto specifications, and it is discussed that the allowable deflection criterion, 7.5% Of the pipe diameter, controls the minimum soil cover requirement. It is also discussed that by increasing the corrugation's moment of inertia or improving the quality of the soil or both the minimum soil cover requirement canbe reduced. Design solutions are obtained with aid of cande, the plane strain computer program. A new methodology is introduced to account for the three-dimensional effects of tire loads (h-trucks) in the context of a plane strain analysis. The design/analysis methodology is shown to compare favorably with field data for the shallow buried plastic pipes with simulated h-20 truck loadings. As a final result, design tables and guidelines are presented that specify the minimum required soil cover as a function of pipe diameter, h-truck loading, corrugation section properties, and soil type and percent compaction. Also, the results are extended to railroad loadings. This paper appears in transportation research record no. 1288, Geotechnicalengineering 1990.
Abstract