RIVER EMBANKMENT PROTECTION USING TECHREVETMENT® TECHNOLOGY AT KARNAVATI RIVER

GMR Power and Urban Infra Ltd.

2022 (50 Years Design Life)

• Terre Armée India

         (Reinforced Earth India Pvt. Ltd.)

Dedicated Freight Corridor Corporation of India Ltd. (DFCCIL), a Special Purpose Vehicle (SPV) of the Ministry of Railways, Government of India has planned the Implementation of Dedicated Freight Corridors connecting Delhi with Mumbai on the Western side and Ludhiana with Kolkata on the Eastern side of India. Near Vindhyanchal Railway station there is a local river Karnawati, which flows very close to the Eastern DFCC track. During monsoon season this river reaches a high flood level, affecting the embankment supporting the Railway track.

Initially, the main contractor constructed a gabion wall to protect the embankment of the DFCC track but was unsuccessful and got washed away with the water flow. After the gabion failed, the client needed a solution that can withstand extreme flooding conditions.

The construction of TechRevetment® took place during monsoon and the water level started rising during installation.

Terre Armée India project team had to be on alert to assess the water level almost all the time. The installation had to be taken up underwater.

After completing site survey, Terre Armée India proposed a TechRevetment® system to protect the river bank and withstand the extreme flood condition. The river channel had an ox-bow curve and the river was flowing almost perpendicular to the bank at the upstream entry location to the site. This had a major damaging impact on the embankment.

The Terre Armée India team had to understand the behaviour of the river flow and design the mattress accordingly to mitigate the risk of scour. The design discharge of the river was 1885 cum/sec and the mean stream velocity was 3.5m/sec. TechRevetment® (150 thick. Grout filled Articulating Block (AB 600) Mattress with Bi-directional and Uni direction cable on the launching apron and on the embankment slope respectively) was proposed as bank and scour protection along a length of 354m along the DFCC track including 210 m of the straight embankment and 144m in curved portion. The key advantage of underwater installation helped us to complete the project in the stipulated time even when the river was in full flow.