With the availability of geotextile with a wide range of pore sizes and permeability, it is a comparatively simple matter to select a fabric that will filter the soil to be drained , where the drainage trench is simply lined with the filter fabrics and back filled with an aggregate that is coarse enough to act as a drainage medium .
Choosing the right geotextile
In order to choose the right geotextile, its precise function must be known. Will it be used for separation ,or for reinforcement etc.? Will it be subjected to high or low stresses ? Is the subsoil firm or soft ? etc. All these important questions which have a bearing on the choice of geotextile and of the raw material . Because only a correctly choosen textile will satisfy the requirements