Modulus of Soil Reaction Values for Buried Flexible Pipe

A table of modulus of soil reaction (E') values for use in the Iowa Formula has been empirically developed by the Bureau of Reclamation. Use of the methods and values suggested can reasonably predict the initial (no time effect) deflection of buried flexible pipe under fill up to 50 ft (15 m). The E' values vary according to the type of soil placed beside the pipe and the degree of compaction. The accuracy of predicted deflections varies according to the degree of compaction. Laboratory soil container tests and data from over 100 field installations were used in the investigation.