OWNER:
ADA Infrastructure
ENGINEER:
Cundall
GENERAL CONTRACTOR:
McLaren Construction
MAIN FIGURES:
c.7,000 BMCs
Performance Specification: Post construction settlement < 50 mm
Project Details
Based in East London – the site comprises of the construction of a new 210 MW Docklands data centre campus designed for emerging AI workloads. The campus includes three separate buildings, substation, aux. structures and a large external parking supported by a dedicated canopy.
Ground Conditions
Given its previous use in the docklands, the site had an extensive array of obstructions comprising of buried foundations, tanks and timber piles, with additional risks related to contaminates and gas pockets that had to monitored continuously throughout the works. Ground conditions at the site comprised up to 6m of mixed granular/cohesive fill. This was locally stiff at the surface, requiring preboring at times. This was underlain by very soft and soft alluvium deposits, followed by London Clay.
Solution
During the initial tendering stage, Bi-Modulus Columns were proposed by Menard as a value engineering alternative to the use of piles and a traditional earthworks program. Due to the remediation and demolition works, the site had to be raised by up to 2m to reach final elevations. The BMCs were utilised to external areas to support the weight of the 2m upfill, while also controlling total and differential settlements within the 6m of made ground. The upper stone portion enabled the post ground improvement works and facilitated the installation of the utilities. Along with coordinating around obstructions, every utility invert had to be verified during the design phase to ensure the stone portion extended sufficiently to depth to prevent conflicts. Menard’s Omnibox system allowed for the monitoring of the stone depths and QA/QC. The BMCs were installed across 40,000 m2 of external area, in support of the extensive networks of underground infrastructure, tarmac and canopy foundations. (CFA piling has been installed beneath building areas). The works were phased in multiple visits to accommodate the ongoing remediation works, coordinating with Network Rail and the closure of the neighbouring roads / concrete plant. The substation externals are to be installed under a separate contract by Menard.
Sustainable Development
Alternative to traditional earthworks dig/replace program and piling.
