Sainsbury's Soil Nailing

The construction of a new flagship Sainsbury’s store is nearing completion in Newport South Wales, planned to coincide with the 2010 Ryder Cup, being hosted at the nearby Celtic Manor Resort.

Kier Group contacted Phi Group at an early stage to help develop a solution to remove an existing 6.0m high retaining wall adjacent to the highway, whilst also cutting into the exposed embankment to create a larger car park. Various solutions were investigated, including piling behind the existing wall, but access issues made these solutions impractical and expensive. 

Phi Group proposed the use of its Andacrib concrete crib retaining wall system. A tough durable system, it is has been used on many projects, including highways and rail projects where a 120 year minimum service life is required. The system can also be landscaped using planting bags that will soften the visual impact of the retaining wall, so is also very popular on housing and retails schemes alike. The Andacrib system is also very quick to construct, with build rates of 30m² face area per day.

A particular restraint was an existing public highway situated as close as 10.0m away from the line of the proposed Andacrib retaining wall. As ever, the temporary earthworks issues were paramount, with the local Highways Authority needing to be satisfied that any solution proposed would have no impact of the carriageway above. Phi Group proposed the use of temporary soil nails to stabilise the temporary earthworks profile as the excavation for the proposed Andacrib concrete crib retaining wall was undertaken. Phi Group undertook the design, supply & installation of both the Andacrib retaining wall and the temporary soil nailing. This was a particular benefit for Kier as it meant that all retaining wall works were in one contractor’s package. Keller Foundations, Phi Group’s sister company, also carried out a considerable amount of piling works for the new store foundations.

Phi Group has completed several retaining structures for Tesco, Sainsbury’s and Asda projects this year.