December 2015: UnPS, the Tunnel and Shafts designer of the Lee Tunnel, was presented with the ‘Design Innovation of the Year Award’ at the 2015 NCE Tunnelling & Underground Space Awards for ‘Lee Tunnel – Construction of the Secondary Lining using SmartShell™’. This recognises the innovative tunnel lining system UnPS developed.
The system, known as SmartShell™, is a steel fibre reinforced concrete which was applied as a secondary lining to the Lee Tunnel project in London. The tunnel will be subject to large forces, such as water surges, so the secondary lining had to be heavily reinforced. UnPS identified that challenging the traditional design and construction methodology of the secondary lining would make significant improvements to the delivery of the project, and performance of the finished tunnel.
UnPS, through an extensive testing and analysis programme, designed a tunnel lining system which removed the requirement for steel rebar. This eliminated the risks associated with steel bar fixing which resulted in a simpler and safer construction methodology. The SmartShell system has brought a multitude of design, cost and efficiency benefits, including the elimination of 15,000 tonnes of steel rebar, £13.5 million saved on material costs, and a significant saving on construction time. These successes were only realised through working in a collaborative project team who were highly receptive to the SmartShell™ philosophy and the great benefit it could – and did – add to the project.
The judges said “This innovative piece of kit is repeatable on tunnels worldwide and has the potential to dramatically cut costs and time when it comes to tunnel linings. On this project, this innovation cut 60 days from the programme and saved £13.5 million in material costs alone. Everyone in the business of installing tunnel linings should be looking at this.”
Professor Colin Eddie, Managing Director of UnPS, said: “We have designed and implemented a system which has redefined the way projects such as these are constructed. The SmartShell™ system has added an incredible amount of value to the Lee Tunnel project and we’re delighted to have been recognised by the wider industry.”