The client was constructing the extension of the Aligarh-Ghaziabad section of the National Highway NH-91 in Uttar Pradesh. The highway extension converts the existing two-lane carriageway into a modern four-lane highway. The side slopes of the highway embankments required protection against erosion from rainwater runoff flowing down the slopes. Since the right of way was restricted, the slopes were steep as much as 1.5H: 1V with a maximum height of 12 m.
Stone pitching is the conventional erosion control for bridge abutments. Stone was not available near this site and was required to be brought from quarries with long leads, and transport costs were prohibitive. Also, considering that the slopes were as steep as 1.5H:1V, it would not have been feasible to have stable pitching.
Slope protection with StrataWeb® geocells infilled with vegetated soil was a more practical and long-term solution under the circumstances. Geocells are an effective way to protect the soil along a slope from erosion by providing a stable layer of confined material over the surface. StrataWeb® geocells of 75 mm depth with local soil infill were proposed to support vegetation growth and provide a green finish so that the infill does not get washed away.




