ICAR-National Institute of Research on Jute and Allied Fibre Technology, Kolkata, India
Online published on 30 January, 2020.
A multi-fibre approach has been adopted in conventional geotextiles to engineeraneco-sustainable product(s) possessing the improved geotechnical properties for enhancement of performance of earthen structure through soft revetments. Hybrid geotextiles comprising of juteand synthetic (polyolefin) were used together to minimize the disadvantages of each of the components by incorporation of their complementary advantageous properties. Hybrid geotextile was developed and compared with conventional 100% synthetic geotextiles. The geotextile contains at least 60% natural component having tensile strength10 kN/m and apparent opening size (AOS) of 180–200 micron. The above geotextile initially acts as a filtration layer and thereby assist in the formation of hard filter cake at the inner face of the geotextiles and after 6 months of degradation of jute, open structure synthetic part acts as durable reinforcing element for the entire soil structure and higher porosity of the cloth assists faster and better vegetation. Placing of seamless geotextile tube made of polypropylene tape filled with moist river sand as anchor trench-cum-toe guard with graded aggregates and back-filled of soil and sand, adds further reinforcement to the earthen structure. A cushion of soil to encourage vegetative growth, through turfing/grass sodding gave additional revetment of top soil geotextile and bottom soil by deep insertion and interweaving of grass roots. The woven fabric with apparent opening size (O95) of 180–200 micron successfully resisted the soil erosion thus helps in better confinement of the bund. Blended geotextile seliminates clogging off, and reduces the phase difference, thus are less slippery nature and provides better point to point contact for top soil and back soil. The developed geotextiles were tested through a large field trial for reconstruction of a part of the bank of river Mayurakshi at Birbhum, W B, India. The performance of the geotextiles is being monitored for last 10 years.
