Old Oak Common Station: A Geotechnical Triumph for HS2

The construction of Old Oak Common Station, a key part of the UK’s High Speed 2 (HS2) project, has reached a significant milestone with the completion of its foundations. This crucial stage, which underpins the entire structure, highlights the geotechnical expertise and engineering precision required to support a future transport hub of this scale.

Spanning 850 meters, the underground station base is designed to accommodate six high-speed rail platforms. Constructing the 45,000m² base slab, which reaches a thickness of nearly 2 meters, required an enormous 76,000m³ of concrete and 17,000 tonnes of reinforced steel. Over 91 individual concrete pours, a team of steel fixers, joiners, and engineers worked tirelessly to ensure the stability of the structure.

The geotechnical challenges of the site were immense. Excavation, completed in mid-2024, involved removing 1.3 million tonnes of London clay, a task managed by Expanded. To ensure long-term structural integrity, a drainage layer of shingle was installed before a reinforcement mat was set, followed by meticulously hand-fixed steel layers to resist subsidence and soil movement.

With the foundation now complete, efforts are shifting to building the six HS2 service platforms. Prefabricated slabs, manufactured off-site, will be installed starting this spring. Additionally, work has commenced on the station’s ground floor, setting the stage for the wider transport infrastructure that will enhance London’s rail connectivity for generations to come.