The Deepcar development near Sheffield represents a significant regeneration effort on land historically used for mining and heavy industry. The site is characterised by deep made ground, variable fill materials, and the presence of historic mine workings, all of which contribute to highly challenging geotechnical conditions. As part of the wider transformation of the area into a new residential community of approximately 400 homes, Tailor Engineering was appointed to deliver the design of four major segmental retaining walls forming key elements of the site’s infrastructure.
The design process was informed by extensive site investigation, which provided a detailed understanding of the subsurface conditions and the geotechnical risks associated with the site’s industrial legacy. These findings guided the development of a robust engineering strategy capable of ensuring long‑term stability and performance of the retaining structures.
For the taller walls, ground improvement using rigid inclusions (RIs) was adopted to address the poor load‑bearing capacity of the made ground and to mitigate settlement risks. The RIs were designed and installed by a specialist contractor and were configured to enhance both global stability and overall deformation/settlement control beneath the proposed structures. Their installation created a reinforced soil mass capable of supporting the substantial loads imposed by the retaining walls and related development works.
Above the rigid inclusions, Tailor Engineering designed a reinforced Load Distribution Mattress (LDM), also referred to as a Load Transfer Platform (LTP). This system comprised granular structural fill reinforced with perpendicular layers of high‑strength geogrids, each with a tensile strength exceeding 250 kN. The LDM ensured effective transfer of loads from the retaining wall foundations into the improved ground, providing uniform settlement behaviour and enhancing overall structural reliability.
The retaining walls themselves are significant engineering works, with some reaching heights of up to 9 metres. Their design incorporated not only the structural requirements of the wall system but also the need to support a piling working platform for the residential units to be constructed above. This dual‑function design required careful coordination between geotechnical, structural, and construction teams to ensure compatibility and safety throughout the build sequence.
The Deepcar project demonstrates the successful application of advanced ground‑improvement techniques and reinforced soil technologies in the redevelopment of complex brownfield sites. Through close collaboration with the client, McAuliffe Group, and the specialist ground‑improvement contractor, the project team delivered a technically robust solution that enables the safe and efficient construction of critical retaining structures within a challenging geological environment. The work at Deepcar forms a key step in transforming a former industrial landscape into a stable and resilient foundation for a new residential community.
