Invention of geotextiles has opened a new era in the growth and development of a variety of human activities related to construction of embankments for roads, railways and canals; bank protection works etc. and retrieval of areas by landfills. The word geo implies the end use associated with improving properties and performance of engineering works founded in soil and the word textile implies that the product is made from man-made fibre. Allied products related to Geosynthetics are Geotextiles, Geogrids, Geomeshes, Geonets, Geomats, Geotubes, Geomembranes, etc which are applied in the foundations under various conditions.
The filter can be made using either a proper mixture of well graded sand, gravel or a specially designed textile. The former is referred as graded filter and the later as geotextiles filter. The difficulties faced by engineers in construction and maintenance of traditional graded filter are well known. However, it was noticed by the authors during their interaction/experience that some practicing engineers are still preferring to use graded filter than geotextiles due to lack of adequate information and appropriate technology. Geotextile has a large variety and can be broadly classified into two categories as woven and nonwoven.
The authors have carried out a number of studies for deriving bank protection measures for rivers in different states of India, and selected geotextiles for their application in the form of filter. This paper presents a case study for application of geotextiles as a filter. The studies were carried out for deriving bank protection measures for intake structure of thermal power plant located on bank of an alluvial river from north India. Different aspects of studies are delineated, and aspects related to deriving design specifications of geotextiles filter to suit the site conditions are highlighted.
This paper was originally presented at ICTN2010 IIT Delhi by Chief Research Officer V G Bhave & Senior Research Officer M V Chhatre of Central Water & Power Research Station, Khadakwasla, Pune, India.