The purpose of geo-textiles with reference to drainage and filtration is simply to retain soil while allowing the passage of water. When geo-textiles are used as drains, the water flow is within the plane of the geo-textile itself i.e., they have high lateral permeability. At the same time, geo-textiles must possess adequate dimensional stability to retain their thickness under pressure. The life of pavement of highways/airfields etc is affected by the time for which the water remains under the structural section and its drainage system which is responsible for the removal of free water which is fed directly from ...View More