An In-Plane Permeability Test for Geofabrics

Abstract

A test device and method for a practical, accurate in-plane permeabillty test for woven and nonwoven geotextiles has been presented. The test apparatus uses parallel flow of water through a geofabric specimen measuring 20cm by 20cm and is capable of testing not only a single layer of geofabrics but multiple layars and soil-fabric-soil composites. The range of vertical stress that can be applied to the specimen is up to approximately 5kgf/cm². Based on the comparison with the results of bentonite-coated specimens, it is concluded that no significant leakage occurs along the boundaries of a geofabrics specimen during the in-plane permeability test. The coefficient of permeability of geotextiles is maintained constant under a constant vertical stress applied to their plane, but decreases markedly with increasing stress.