Gujarat, India | National Highways Authority of India (NHAI)
The National Highways Authority of India (NHAI) was upgrading the highway system in various stretches along Ahmedabad – Vadodara Expressway in the state of Gujarat.
Highway embankments are an integral part of the motorway to maintain the finished road levels. In this project, the embankments were provided with 1:1.5 (V:H) side slopes for the stability of embankment. Erosion of slopes of road embankment due to rainfall and surface runoff of precipitated water was one of the major problems that need to be addressed during the construction of highways / road embankments. If neglected, the progressive erosion of slopes may lead to overall instability of the slope of road embankment affecting the service life and performance of the road pavement too. National road construction guidelines recommend surface protection in any case where there is a chance of surface erosion.
Conventionally, concrete lining / 300mm stone pitching are used for the slope erosion protection. TechFab India suggested usage of Techcell Geocell of 712 x 100mm type, which is infilled with vegetative soil as an appropriate solution for effectively protecting the embankment slope as Geocell is cost-effective, long lasting and eco-friendly. This solution is in accordance with the provisions of Section 705 specifications of MoRTH 5th revision. By using geocell confinement system, the slope protection measures can be optimized in terms of thickness and further improve the performance of protection measures due to its confinement effect. The infilled geocells provide a stable layer of confined material over the slope surface. They promote vegetation growth to provide a green surface which also protects against erosion. At the toe of the slope geocell was embedded in the subgrade. A collecting drainage system was also constructed which comprised of Geocells infilled with concrete over Nonwoven Geotextile to improve down-slope stability against high water flow.
The Project was completed successfully and has been serving its purpose. The slopes are now green and aesthetically pleasing.
