With over 24 years of experience spanning geoenvironmental and geotechnical engineering, Gary Shawley, Associate Director at Lucion, explores the critical ground considerations that can make or break data centre developments, and explores why comprehensive site investigation is the foundation of successful digital infrastructure delivery.
The Foundation Challenge That Makes or Breaks Data Centre Projects
With over 24 years of experience spanning geoenvironmental and geotechnical engineering, Gary Shawley, Associate Director at Lucion, explores the critical ground considerations that can make or break data centre developments, and explores why comprehensive site investigation is the foundation of successful digital infrastructure delivery.
The Hidden Foundation Challenge
The UK’s data centre sector is experiencing unprecedented growth. According to Statista, there are an estimated 500+ data centres across the UK, with more in the pipeline as demand for digital infrastructure accelerates. Yet for all the focus on cooling systems, power redundancy, and network connectivity, many developers underestimate the single biggest technical risk to their project, the ground itself.
Data centres are, quite simply, heavy structures. Extremely heavy. The combination of densely packed server racks, substantial cooling infrastructure, backup power systems, and the reinforced concrete required to house them creates loading conditions that push soil to its limits. You’re not dealing with a typical building. You’re dealing with a structure that demands exceptional geotechnical consideration from day one.
The challenge isn’t just about whether the ground can support the load – though that’s obviously critical. It’s about understanding how the ground will behave over the 20-30 year operational life of the facility. A few millimetres of differential settlement might be acceptable for the vast majority of conventional structures. In a data centre, it can misalign critical equipment, distort raised floors, and disrupt carefully calibrated cooling distribution. The tolerance for error is minimal, and the cost of getting it wrong is substantial.
Why Presumed Values Won’t Cut It
Having worked on many sites for some of the biggest data centre operators in the UK, one of the most common mistakes I see in development projects is over-reliance on limited information which is often inaccurate, not defensible and provides more questions than answers. There can be no reliance on general published data or rules of thumb when dealing with such critical structures.
Presumed values and published data don’t account for what’s actually happening beneath your site. They can’t tell you about the weak clay layer sitting 4 metres down, the seasonal groundwater variations that affect soil strength, the poorly compacted Made Ground from previous industrial use, or the localised soft spots/hard spots that could cause differential settlement under concentrated loads.
This is where site-specific investigation becomes non-negotiable. Our approach at Lucion focuses on planning and implementing a cost-effective ground investigation that provides a robust ground model derived from a host of investigation techniques be it shallow trail pits, deep boreholes or CPT coupled with on site in-situ testing, laboratory testing to determine soil and rock properties, groundwater monitoring to accurately record groundwater regimes and other specialised procedures and tests like thermal resistivity testing and geophysical analysis.
All this information is collated, analysed and put through detailed calculations and professional software packages so critical but understandable information can be provided to Clients and stakeholders.
Deep Investigation for Deep Understanding
The investigation programme for a data centre site often needs to go deeper – literally and figuratively – than many developers initially anticipate. Throughout my career working on everything from university accommodation to a 120-metre deep opencast pit reclamation scheme, I’ve found that data centres present some of the most demanding ground investigation requirements.
Deep Boreholes
Deep boreholes are essential. We typically adopt a multidisciplinary approach to ground investigations for Data Centre Sites and due the high floor slab and foundation loads required boreholes progressed by cable tool percussive and rotary drilling techniques can often extend to 40 metres or more to determine bedrock depth, identify all soil strata, and understand the complete soil profile. You need to know not just what’s immediately beneath your foundation level, but what’s beneath that, because weak strata at depth can still influence settlement behaviour given the size of the building footprints and the loads applied.
The continuous soil sampling and retrieval of high-quality rock core means that detailed logging can be completed and laboratory testing to determine shear strength, internal friction angles, compressibility, and other crucial engineering properties can be obtained. It’s this data, not presumed values, that allows us to calculate site-specific safe allowable bearing capacities, immediate, primary and secondary settlement regimes and a whole host of project critical data to allow civil and structural engineers to work alongside us with confidence.
Geophysical Surveys
Advanced geophysical surveys complement intrusive investigation by providing continuous data between exploratory locations. Techniques like seismic refraction, electrical resistivity, ground location specific geotechnical testing, along with historic site investigation, identify variations in ground conditions across the site. I’ve seen projects where geophysics revealed buried structures or voids that weren’t apparent from boreholes alone, findings that saved months of delay and substantial redesign costs.
Thermal and Electrical Resistivity Testing
Thermal and Electrical Resistivity Testing addresses the unique requirements of data centres. These facilities generate enormous heat loads and understanding how the ground conducts heat influences both foundation design and cooling system specification. Electrical resistivity testing informs earthing design for the sensitive electrical infrastructure that defines these facilities.
Trial Pits & Trenches
Trial pits and trenching provides direct visual inspection of shallow ground conditions, particularly valuable for assessing Made Ground or identifying buried structures from previous site uses.
Many prime data centre locations sit on former industrial land, and understanding what’s been left behind, including hazardous materials such as asbestos, is crucial for both foundation design and contamination assessment.
But it doesn’t stop there. It’s not just the data centre itself that needs to be considered. Roads, car parks, utilities installation, all these elements need to be considered as part of the foundation of the site. CBR testing and structural implementation are essential to the final success of the project.
Getting It Right From the Start
Each site investigation for a data centre project is unique. Hydrological and geotechnical elements massively vary from site to site so it’s essential to understand what’s going on beneath the ground before breaking ground. Discovering you’re building next to a water source or high-water table, poor soils causing high earth resistance or differential settlement issues can all be non-starters.
Construction delays translate directly into lost revenue. There’s no room for ground-related surprises. Comprehensive geotechnical investigation is fundamental risk management that protects programme, budget, and operational performance.
As the UK’s data centre sector continues its rapid expansion, the projects that succeed will be those that recognise a simple truth, you cannot build digital infrastructure without first understanding the ground it stands on.
For comprehensive ground investigation that de-risk your data centre project, drop me an email at [email protected].
