Thousands celebrate UK's longest road tunnel May 2011
Paula Wallis, TunnelTalk
Thousands walked the tunnel
- The turnout was far greater than anyone expected. Thousands showed up to mark the completion of the Hindhead road tunnel beneath one of the country's most scenic spots in southeast England.
- The tunnel is set to open to traffic in July, but before that, more than 6,500 people walked the 1.9km (1.2 mile) tunnel last Saturday (May 14). A steady stream of walkers entered the tunnel from the south to get a close up look at the £371m project. They walked by plaques marking the location where the two sides met during excavation, as well as the tunnels deepest point, 65m (213ft) underground.
- Balfour Beatty won the £186 million twin tube tunnel contract, which includes 16 cross passages, one every 100m (328ft), and 34 emergency niches. About 90% of the tunnel was excavated from the north portal through sandstone and about 10% from the south portal through sand. The SCL (sprayed concrete lining) tunnel includes a spayed-on waterproofing system. The waterproofing system and other value engineering helped bring the project in ahead of schedule and below budget.
- In December 2010, the project received and International Tunnelling Project of the Year award.
Spay-on waterproofing application
- Judges praised the design and delivery of the project. "This project was very well planned and executed with great thinking around safety," said one judge. "The spray-applied waterproof membrane was a tremendous step forward for UK tunnelling and underlined an altogether innovative design and construction process." Another judge said "the focus on economic construction saved over £12 million and good community relationships ensured that the work in this tricky and highly congested road network progressed smoothly."
- The tunnel is part of the 6.7km A3 bypass to relieve traffic congestion, where the dual-carriage motorway narrows to two lanes through the scenic Devil's Punchbowl, which is a designated area of outstanding natural beauty in the UK. A major bottleneck will be eliminated when the £371 million motorway opens in July.
- UK applies spray-on waterproofing - TunnelTalk, Mar 2010
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