IRB Amritsar Pathankot Toll Road Ltd. was executing the extension of NH-15 from two lanes to four lanes. The stretch of 102 km includes several kilometres of the carriageway on embankments. The embankments were constructed of local soil, which is generally non-plastic silty fine sands. Some of the embankments ramp-up to underpasses and over bridges. Side slopes of the embankments needed to be protected against erosion.
The wing walls to support the side slopes at the underpass comprised of a reinforced soil system with StrataGrid™ geogrids and precast concrete StrataBlock™ fascia. Considering the traffic surcharge and other loads, the surface of the slopes was susceptible to erosion. There was severe soil erosion during the rains due to run-off along the slope, which manifested as rain cuts.
A long-term solution required the slope to be protected with a non-erodible liner such as plain concrete, which would be difficult to lay the concrete on the slope, as the concrete panels would be susceptible to cracking and deformation due to movement of the soil embankment. Therefore, it was proposed that StrataWeb® geocells be laid on the slope.
StrataWeb® not only facilitated in repairs of the damaged slope but also proved to be a long-term erosion protection solution. The solution proved to be the most economical and speedy resolution to an otherwise distressing issue. The solution provided virtually maintenance-free slopes against the forces of nature.
