Asda is one of the leading supermarkets in the UK and the company has over 300 superstores nationwide. One of the latest Asda Superstores to be opened is in the Lidget Green area of Bradford and features a 38,000 sqft superstore, a petrol station and a car park for over 400 cars.
Space was at a premium on this site, so the team had to maximise the usability of the land at the northern end of the site to make the most of the space available. In this area the land naturally dips down towards a beck and the decision was made to level this area to accommodate car parking spaces and to create an area for a service yard and access road.
Levelling the land
The key aim of this project was to create as much usable space as possible adjacent to the new superstore. To do this, engineers designed a 98 metre long earth retaining wall, which would reinforce the soil and create an additional levelled area to the rear of the superstore. To minimise costs and time spent removing waste from the site, waste materials were retained on site which meant around 900m3 of existing lime stabilised material was used within the reinforced soil structure. Retaining waste materials on site was the ideal solution for this project, as geogrids are very effective when used with stabilised lime fill materials.
Expert help from SIG Geotechnical Centre
Andrew Thompson, Geotechnical Business Development Manager North, worked on the project and explains why the geogrid structure was such an effective solution, “There were a number of elements to this project which needed to be in place in order for the area to be levelled successfully. To begin with, we needed to construct an 8 metre high permanent facing structure with a 68 degrees face angle to retain the material. We did this using geogrid reinforcement in combination with galvanised facings and erosion control matting.”
He continues, “To ensure the structure was strong enough, we used a geogrid soil reinforcement system which features monolithic flat polymer reinforcement bars. These bars are uniformly extruded and drawn to achieve a high modulus and strength at low elongations.
Finally, erosion control mats were installed to further protect the slope from erosion. These control mats feature a dense mesh filament core which retains soil fill over its entire area and depth. The product also prevents soil washout whilst retaining moisture to support root development, which will provide further strength once established.”
The project took just 17 days to complete and the materials used are designed to provide effective reinforcement to the site for at least 120 years.