TENSAR INTERNATIONAL has supplied geogrid for embankments associated with a new housing development and business park built over redundant mine workings near Glasgow.
The geogrid is being used for load transfer platforms forming foundations for bridge approach embankments for a £2.5M access road.
Redevelopment of the Cardowan Colliery site, once the largest colliery in Scotland, is being carried out by main contractor Morrison Construction.
Provision of a new public access road was a condition of the planning consent. It involved bridging a live railway running alongside the site.
Contractor Keller Comtec won the design and construct contract for the embankments. Foundation construction was particularly difficult because of the close proximity of the railway and the underlying soft peaty soils.
The original plan was to support the 8m high embankment on a grid of concrete driven piles with concrete pile caps or a concrete raft. Instead, geosynthetic manufacturer and supplier Tensar and Comtec came up with an alternative design that involved capping the piles with a load transfer platforms built from Tensar geogrid reinforced fill, greatly reducing construction time and cost.
Different types of geogrid were used according to the embankment height. Tensar biaxial reinforcement with good quality granular fill was used where the structures were up to 4m and Tensar Basetex was used where they were over 4m.
Costs were further reduced by reinforcing the embankment side slopes with Tensar uniaxial grid to allow them to stand at 450, reducing land take and reducing the amount of fill and the number of piles needed.