Long-term clogging behavior of non-woven geotextiles with silty and gap-graded sands

Non-woven geotextiles are generally used for the protection of synthetic liners in sanitary landfills. In this application the geotextiles perform as a filter and drain for the leachate collection system. Since geotextiles play a major role in landfill design, they should be properly selected to obviate any clogging problems. Filtration criterion for the non-woven geotextiles are still evolving. The existing filter criteria are not applicable for silty and gap-graded soils. In this paper, the results are presented for six different non-woven geotextiles which are tested with eighteen different gap-graded soils to evaluate long-term filtration behaviors. Microstructure analysis results are provided for a better understanding of the clogging mechanism of non-woven geotextiles.