Mott MacDonald to design Thames Tideway East

29 January 2016

GREAT BRITAIN – Mott MacDonald will design the eastern section of the Thames Tideway sewer tunnel in London. The section will be constructed by a joint venture of Costain, Vinci Construction Grands Projets and Bachy Soletanche.

The east section package includes the construction of two TBM-driven tunnels - a 5.5km section of the main 25km tunnel and a 4.6km connecting tunnel for combined rainwater and wastewater. The main tunnel will have an internal diameter of 7.2m, while the connecting tunnel will be 5m. The project will be 45 to 65m below ground. The east section also requires five shafts from 17 to 25m in diameter sunk to 72m using diaphragm walls.

According to a spokesman, an optimisation phase, which includes design and methods, is almost completed and the design team are delivering the first conceptual designs using state-of-the-art building information modelling models and processes. The works are scheduled for delivery in 2023.

Michael Francis, Mott MacDonald's project director, said: "It is fantastic to be involved in the creation of one of London's most significant infrastructure projects. The East works package is the deepest section of the project, with tunnels driven by slurry TBMs deep in the chalk up to 70m below the water table. The deep shafts will be constructed using diaphragm walls and the complex hydraulic structures to divert flows require soil mixing ground treatment, secant piles and high-quality concrete meeting the 120 year design life."

Thames Tideway section divisions