The ramps of the grade separators are constructed either as embankments with natural slopes or as reinforced soil walls. In the case of partial walls, where sloped embankments are supported on reinforced soil walls, the embankment slopes needed to be given adequate protection against soil erosion, which could otherwise damage the fascia of the underlying reinforced soil wall and also induce seepage into the system. The slopes of the embankments were of the order of 30° with the horizontal. The reinforced soil walls supporting the embankments were as high as 10 m. The heights of the embankments were of the order of 5 m.

Considering the time factor, economy and technical issues, it was decided to adopt slope protection using StrataWeb® geocells filled with PCC.

A slope of 30° (1.73H: 1V) is steeper than the conventional 2H: 1V slope which is generally considered for road embankments. However, it is a moderate slope when it comes to lining with geocells which can cover slopes as steep as 1H: 1V. This factor clinched the decision to consider geocells as a slope protection method. StrataWeb® style SW 712-75 was considered.

The cell depth of 75mm was found optimal as a greater depth would have increased the weight of the geocells and the concrete in-fill, thereby increasing the downward force. A shallow depth also brought about a reduction in the cost of concrete.

The work was completed within a short span of ten days with minimal labour.