Waterproofing Solution for Tunnels 

BASF MEYCO Underground Europe recently held a two-day designer workshop for tunneling engineers in collaboration with Balfour Beatty Civil Engineering, showcasing its permanent waterproof single-shell tunnel lining based on sprayed concrete and double bonded waterproofing membrane. Held at Hindhead, England on 24-25 June 2009, the workshop addressed the design issues surrounding the technique and featured the Hindhead highway tunnel project, where the single-shell waterproof tunnel lining is currently being adopted.

52 delegates from 13 countries including Austria, Switzerland, Greece, Norway, the Czech Republic, Russia, Italy, Qatar and the UK were able to witness the full-scale application of the system in the Hindhead tunnel and observe its technical advantages firsthand.

BASF speakers included workshop chairman Karl Gunnar Holter, Dr Thomas Kothe, Claire Verani and Christof Ziegler, with other presentations being made by representatives from iC-consulenten (Salzburg, Austria), Amberg Engineering, (Regensdorf, Switzerland), Mott MacDonald (London, UK), Monod+Piguet & Associes (Lausanne, Switzerland) and Balfour Beatty.

Said BASF’s Richard Foord, Project Manager – Underground Construction UK & Ireland: “The Hindhead Tunnel project using the new technology of a spray-applied waterproofing membrane illustrated the great vision and faith that Balfour Beatty has shown in the system. What has resulted is a very deep-seated, strong partnership with BASF. Since getting involved at the value engineering stage in 2004 a durable partnership has evolved that has added value to the project. Balfour Beatty is justifiably proud of what has been achieved and will take the experience forward in the future for other major infrastructure projects.

Concluded Richard: “The workshop delegates were extremely impressed by the project, and even the sceptics were silenced!”

The Hindhead project is a major scheme for the UK Highways Agency and will complete the dual carriageway link between London and Portsmouth in the South of England. The first new bored road tunnel project in the UK for 30 years, the 1.8km long twin bored tunnels are located under the Devil's Punch Bowl, an area of outstanding natural beauty which has special status as a Site of Special Scientific Interest. The whole area will be reinstated on completion of construction and the existing road around the Devil's Punch Bowl will be closed, bringing considerable environmental benefits to an internationally prized area.

The main tunnelling works started in February 2008 and both tunnel bores broke through on 26 February 2009. The tunnel is planned to be open for traffic in mid 2011.