Dealing with Sabkha - The Smart Way

Dhafra, UAE

Link Road Upgrade E11 to Madinat Zayed 

The link road connecting the E11 Madinat Zayed was to be rehabilitated and widened. The road improvement project was let as a design build contract. For this section of road over sabkha (see left) the contractor was faced with having to excavate the existing embankment and rebuild a wider embankment, having first removed a layer of sabkha across the full embankment width over a 7km length. The engineers were seeking a less expensive, more sustainable, and quicker approach that would minimise road closures.

Tensar Solution

The Tensar solution was in three parts. For the existing embankment, rather than full excavation to remove and replace the sabkha, a Tensar stabilised subbase layer to reduce differential settlement was constructed over the existing embankment after removal of the deteriorated pavement layers. Subbase material obtained from the existing pavement was re-cycled for use in the stabilised subbase layer. For the widening, a Tensar geogrid was placed directly over the sabkha to strengthen and stiffen the embankment above. A Tensar stabilised base layer using locally available marginal fill material was then constructed over the widened embankment to strengthen the full pavement width.

Benefits
  • 15% Reduction in overall cost
  • No importation of expensive high-quality aggregates
  • Reduced construction time due to elimiaton of excavation, dewatering and replacement