A joint venture comprising Cementation Foundations Skanska and Bachy
Soletanche has picked up a £3.6 million contract to construct London’s deepest ventilation shaft in Graham Road, Hackney for the CTRL.
The 54-metre shaft, involving one of the deepest diaphragm walls in the UK, is on CTRL’s contract 220 to provide 7.5 kilometres of twin tunnels connecting Stratford International Station with St Pancras.
The joint venture was awarded the contract because of the combined experience and resource it brings to the project. This includes the sophisticated equipment needed for the construction, such as a state-of-the-art hydromill capable of digging to 54 metres.
Working on a very tight site next to a railway line, the shaft will be constructed using diaphragm walling 1.2m thick and excavated by grab crane down to 12m, then by reverse circulation hydromill to 54m.
As the project is on a tight site next to an operational railway, there has been intense detailed planning prior to the start in mid September to ensure that the work is done safely and to programme. Completion is by Christmas.
Cementation Foundations also has a £30 million contract to excavate a 70,000 square metre diaphragm wall at the Stratford Box section of the CTRL.