At 21 Moorfields, Cementation Skanska acted as a trusted partner, bringing integrity, collaboration and technical expertise to one of London’s most complex construction challenges.

Working above the live Moorgate station with just 15 high-capacity piles and no margin for error, the team combined early-stage collaboration with Landsec, Mace and the wider project team to manage risk and provide certainty. Through advanced engineering, innovative monitoring and a fully integrated approach, the project was delivered safely, on programme and to the highest quality standards — demonstrating how the right expertise and behaviours can simplify complexity and set new benchmarks for urban foundation design.

The project

21 Moorfields is on the northern edge of the City of London on one of London’s most complex sites. Landsec is delivering a 17-storey, 469,000 sq. ft office development to serve as Deutsche Bank’s new UK headquarters alongside high-quality retail space.

To realise this scheme the team developed an industry-first foundation solution — piling through Moorgate station and setting a new benchmark for what can be achieved in constrained urban environments.

The challenge

Severe space constraints limited the design to just 15 permanent piles, creating a high-risk scenario with no precedent for carrying such loads on so few foundations. With no margin for error, any defect could have triggered redesign, delays and additional cost.

Success depended on a fully integrated, collaborative approach. Working closely with Landsec, Mace, Robert Bird Group and Geotechnical Consulting Group, the team aligned expertise from the earliest design stages to manage risk and deliver certainty.

The site spans Moorgate station, serving the Circle and Metropolitan lines, the Thameslink City branch, and the western entrance to the Liverpool Street Crossrail station. At the same time, major Crossrail works were underway directly adjacent. Keeping all stations fully operational throughout construction was critical.

The solution

Working above a live underground station required careful planning and precision engineering. A 120-tonne piling rig was transported into position using a specialist self-propelled modular transporter (SPMT), navigating narrow streets before being lifted onto a temporary steel platform 2 metres above street level.

Three key innovations underpinned the solution:

High load-bearing piles.

The foundation system comprised eleven 2.4m diameter piles, four 1.8m diameter piles and a 1.2m sacrificial test pile. A 200-tonne test frame enabled a maximum test load of 50MN, the highest top-down static load ever applied to a pile in the UK.Instrumentation, including fibre optics and strain gauges, was embedded at multiple depths to monitor performance. All piles were constructed to depths of 58-60 metres under bentonite, with post-construction base grouting to enhance capacity.

Fibre Optic pile monitoring

Cementation’s patented CemOptic system used distributed fibre optic sensing to monitor heat generated during concrete curing, providing real-time insight into pile integrity.More than 14km of fibre optic cable was installed, enabling continuous monitoring throughout the structure’s life and delivering unprecedented data on long-term performance.

Innovative spoil removal

With the station directly below, spoil management was critical. A purpose-built spin-off skip system prevented material falling onto the station roof.

To safely manage excess bentonite during concreting, a bespoke bailing tool was developed and integrated with the piling rig, ensuring controlled removal without risk to the live environment below.

The outcome

Through collaboration, innovation and meticulous planning, the team successfully delivered this complex, high-risk project two months ahead of schedule and on budget.

The solution represents a step change for the industry—demonstrating how constrained sites can be unlocked through engineering ingenuity and providing valuable new insights into pile behaviour and design.

The project received strong recognition from both client and industry. Mace highlighted the team’s proactive, collaborative approach and their ability to manage and mitigate risk from the earliest design stages through to delivery.

Industry recognition

The scheme has been recognised with multiple awards, including UK Geotechnical Team of the Year and Technical Excellence at the 2019 Ground Engineering Awards, followed by the prestigious Fleming Award in 2020. Judges noted the project “pushed the boundaries of design and construction practices to deliver an industry-first foundation solution.”

21 Moorfields

21 Moorfields

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