Volume 19, Issue 2 (June 1996)
Effect of Rib Spacing on Deformation of Profile-Wall Plastic Pipes Buried in Coarse Granular Backfill
Several different types of plastic pipe products were instrumented, buried in coarse granular backfill, and subjected to monotonic, distributed load in the field. During each field test, data were recorded from strain gages, linear variable differential transformers, and earth pressure cells by computerized data acquisition units.
Review of the deflection data from 14 tests revealed a pattern on the initial deflection that can be explained by considering a dimensional ratio between the rib spacing, S, and maximum particle size, dmax. Earth pressure cell readings taken in the springline region appeared to support this. Based on this observation, a recommendation was made that the S/dmax ratio should be either less than 0.6 or larger than 2.6 to prevent excessive initial deflection under relatively low levels of loading.