Filter Criteria for Geotextiles: Relevance and Use

Thm general requirements for filters, both granular and geotextile, in one-directional flow applications and the relevant geotextile properties affecting good filtration performance are presented. The relevance of existing one-directional geotextile filter criteria is also examined. An application involving the specification and performance evaluation of a geotextile for an internal filter in an earth dam, constructed on flyash, where large hydraulic heads were anticipated at the flyash-geotextile interface (up to 10.8 m) validated the use of existing geotextile filter criteria.