The research is an investigation of soil filtration by geotextile fabrics, with the ultimate objective of improving design and long-term performance of underdrain systems in Indiana highways. Experiments were conducted in the laboratory using the best available techniques, Flexible Wall Gradient Ratio Test and Rapid Retention Test, in order to assess soil-filter compatibility and monitor geotextile clogging, for a range of materials and testing conditions. Field information was also collected and samples from highway reconstruction project were examined for their long-term performance. The main findings relate to the influence of the amounts of silt and clay and the state of compaction of the subgrade. Controlling parameters of the geotextile effectiveness are its opening size, thickness and manufacturing style. Based on these findings and information already available from the literature, new design and installation guidelines including filter selection criteria are proposed for non-woven geotextile filters in Indiana highway edge underdrain systems.

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underdrain, edge drain, filter, clogging, non-woven, geotextiles, filter criterion, flexible wall gradient ratio, rapid retention test, SPR-2635

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Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, IN

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