Sainsbury’s Supermarket - Newport, South Wales

Kier Construction ‘try something new’ at Sainsbury’s Newport

A new, 6,500m², Sainsbury’s supermarket has been built on the site of the former Crindau gasworks on Albany Street, half a mile from the City centre of Newport in South Wales. This new store created 200 new jobs in addition to the transfer of staff from the closing inner city store. The rejunenation of the former gasworks site along with other improvements in the area, which played host to the 2010 Ryder Cup Competition at nearby Celtic Manor Resort, were all part of a major local regeneration plan. This major development required a substantial investment by Sainsbury’s in access infrastructure. The site runs alongside the River Usk resulting in complex ground conditions with a rock edge giving way to soft alluvium and peat deposits. Creating a new access road link to the A4042 now provides direct delivery route for HGVs, reducing the number using the Albany Road which helped improve local traffic flows. The access road needed a new bridge to be built over the flood plain and this required substantial embankment construction over the unstable and low-density land. The new access has an elevated ramp 7-8 metres high connecting to the main road, this work required abutment support and some 12,000m³ of Leca® LWA. The ground at this point was very soft and traditional stabilisation was not practical from a depth and time perspective. Surcharging, where significant temporary loading is used to “squash” the soil into a more stable structure, was not appropriate due to the tight schedule to have the property completed in time for the international golf event. The solution, determined by geotechnical consultants White Young Green of Cardiff, was the use of Leca® LWA which is formed by heating and firing natural glacial clay in a rotating kiln at up to 1150°C. The process transforms the clay into lightweight ceramic granules. It is inherently lightweight and therefore reduces ground pressure making Leca® LWA ideal for the difficult soil conditions at this site. Jason Williams of WYG said: “Leca® LWA lightweight granular material, coupled with a Tensar polymer mat geogrid, gave us a very effective reinforced earth result in the shortest time possible. We have a stable embankment construction and the lightest possible loadings on the poor soil. ”The high volume low weight of the Leca® LWA facilitated easy bulk deliveries to the site and swift handling and placement. Andrew Gilmore, project manager for Kier Construction, welcomed the Leca® LWA solution. “This is a very good product, ideal for these difficult ground conditions. It was quick to install, with fast delivery of up to 1000m³ of material per day; 600mm layers going down with the minimum of compaction so that we could press on with the job swiftly.”