Macclesfield, Heapy Street

Menard was initially approached by Howard Wynne Consulting Engineers to develop a ground improvement solution for a new single storey steel portal frame warehouse for H. Whittaker & Sons of Macclesfield Ltd, a long established warehousing, storage and logistics operator. Over its lifetime, the site has undergone several industrial transformations, first operating as a soap mill, then a brickworks, followed by a paper coating mill, and more recently functioning as a haulage and storage depot..

The site was underlain by variable Made Ground and Infilled Ground overlying natural Glacial Till. The Made Ground comprised concrete slabs and limestone aggregate with variable clay, sand, ash, brick and clinker, typically 0.15–2.3 m thick. In the northern area (former reservoir), deeper Infilled Ground of gravels, sands and locally organic clay extended to approximately 3.7 m bgl and was of variable strength. Beneath these deposits, firm to stiff Glacial Till clay was encountered. Groundwater was encountered at depths of around 1.2–3.2 m bgl.

Menard successfully installed circa 200 Vibro Stone Columns (VSCs) across the site to improve the ground and to enable the adoption of shallow foundation solutions. The VSCs were constructed to depths ranging from approximately 2.8 m to 4.2 m below existing ground level, tailored to suit the local ground conditions and foundation requirements. Installation was undertaken efficiently using vibro replacement techniques, forming well compacted stone columns designed to enhance bearing capacity and reduce settlement. The quality and performance of the installed columns were verified by two plate load tests, which confirmed that the required stiffness and load carrying characteristics had been achieved. Overall, the ground improvement works were completed in just under one week, demonstrating a rapid and effective solution with minimal disruption to the wider construction programme.