Abstract
Various types of geosynthetics are used in civil and environmental engineering structures. Especially, geotextiles and their related composites are widely used for drainage purposes under various conditions. Nonwoven geotextiles, woven mats and geonet were used to manufacture the geosynthetics for the purpose of in-plane permeability (transmissivity). The effect of degree of compression loading on the transmissivity of forementioned geosynthetics were examined through laboratory tests. Transmissivities of needle punched nonwoven geotextiles and composite fabrics decrease with the compression stress to 0.2 kg/$\textrm{cm}^2$, 0.5 kg/$\textrm{cm}^2$, respectively and became constant after these values. For nonwoven/geonet, transmissivity decreased to 0.5 kg/$\textrm{cm}^2$ and decreased in case of smaller weight of nonwoven. Finally, the thickness of the above three geosynthetics decreased with compression stress and was influenced by the thickness of nonwovens.
