Embankment Reinforcement with ParaLink

As part of the airport expansion, it was necessary to construct a railway link from the British Rail main line (London - Cambridge) to the new airport terminal buildings.

The spur line was constructed within a glacial valley on a 5m high embankment over highly compressible soils including a layer of peat (up to 7m) overlying chalk. The time needed for a conventional construction technique, namely surcharging the embankment, was unavailable.

The chosen solution was ParaLink reinforcement over a piled foundation which offered distinct advantages over conventional reinforcement materials.

ParaLink 350S and 450S, crosslaid, was placed over pile caps (2.75m centers), the piles being driven through the Terram 3000 used to separate the soft subgrade from the initial stone drainage layer.

ParaLink reinforcement enabled the vertical loading of the embankment to be transferred totally onto the piles and provided lateral restraint.

A conventional construction would have required large diameter pile caps with the addition of raking piles along the sides of the embankment.

ParaLink's reinforcement core (high tenacity polyester) was protected from possible installation damage from the granular drainage blanket by its polyethylene sheath.