Boris opens Lee Tunnel
GREAT BRITAIN – The Mayor of London officially opened the Lee Tunnel in January. The tunnel, the first of two new high-capacity sewers in to serve Britain’s capital is the largest project in the history of Britain’s privatised water industry.
The GBP 678M (USD 971M), 7m-diameter Lee Tunnel runs 6.9km from Thames Water's Abbey Mills pumping station and will act as a collection and storage tank before transferring the flows to Beckton sewage works, which Thames Water has expanded by a further 60 per cent to manage the increased volumes.
The tunnel was dug through chalk at high water pressures and lined with steel fibre reinforced concrete. The team used two 30.6m long shutters to cast a 300mm thick, steel-fibre reinforced secondary lining, reducing the previously bored 7.8m internal diameter to 7.2m. The lining was installed along the entire length of the tunnel. A spokesman for the joint venture added: "The innovative secondary lining technique, first developed on the deep shafts of the project, consisted of replacing conventional reinforced concrete with steel fibre reinforced concrete. MVB successfully developed a workable and pumpable concrete mix with Cemex and the newly developed Dramix 5DTM fibre (by Bekaert) to fulfill the high performance criteria set by the designer."
Mayor of London Boris Johnson said: "This amazing new super sewer is providing the bold infrastructure needed to support the movements of our rapidly growing city. For years our historic Victorian systems have heaved at the seams, muddling along, battling to cope with the increasing rainfall and waste of a modern population. Now the River Thames will benefit from vast improvements to its water quality with less pollution and overflow. Alongside my sustainable drainage work to reduce flooding, the investment in the Lee and the forthcoming Thames Tideway Tunnel are set to benefit Londoners for generations to come."
29 January 2016