Inventionof geotextiles has opened a new era in the growth and development of a varietyof human activities related to construction of embankments for roads, railwaysand canals; bank protection works etc. and retrieval of areas by landfills. Theword geo implies the end use associated with improving properties andperformance of engineering works founded in soil and the word textile impliesthat the product is made from man-made fibre. Allied products related toGeosynthetics are Geotextiles, Geogrids, Geomeshes, Geonets, Geomats, Geotubes,Geomembranes, etc which are applied in the foundations under variousconditions.

Thefilter can be made using either a proper mixture of well graded sand, gravel ora specially designed textile. The former is referred as graded filter and thelater as geotextiles filter. The difficulties faced by engineers inconstruction and maintenance of traditional graded filter are well known.However, it was noticed by the authors during their interaction/experience thatsome practicing engineers are still preferring to use graded filter thangeotextiles due to lack of adequate information and appropriate technology.Geotextile has a large variety and can be broadly classified into twocategories as woven and nonwoven.

Theauthors have carried out a number of studies for deriving bank protectionmeasures for rivers in different states of India, and selected geotextiles fortheir application in the form of filter. This paper presents a case study forapplication of geotextiles as a filter. The studies were carried out forderiving bank protection measures for intake structure of thermal power plantlocated on bank of an alluvial river from north India. Different aspects ofstudies are delineated, and aspects related to deriving design specificationsof geotextiles filter to suit the site conditions are highlighted.

Thispaper was originally presented at ICTN2010 IIT Delhi by Chief Research OfficerV G Bhave & Senior Research Officer M V Chhatre of Central Water &Power Research Station, Khadakwasla, Pune, India.