Heathrow Terminal 2B: delivering the biggest airside basement at Britain’s largest airport

Terminal 2B at Heathrow Airport in London was the largest airside construction project ever undertaken at the UK’s biggest airport. Completed in 2014, it is the first of a series of satellite piers planned for the new Terminal 2 building. Likened to an iceberg, there is far more to the pier underground than above, with large spaces for passenger circulation, baggage handling and a future tracked transit system. The paper describes the design and construction challenges of quickly and safely creating such a large basement structure in a live airport environment. The work involved building a 2 km diaphragm wall, the longest in Europe, and extensive use of temporary ground anchors to free up construction space. This and other design efficiencies led to substantial savings in excavation and materials, helping to ensure the project was delivered within programme and budget.