This March 80 delegates from all over Europe met at a Waterproofing workshop organised by MEYCO Underground Construction Europe, part of BASF. The workshop, held in Trondheim, Norway, explored the design and installation of permanent waterproof single-shell tunnel lining solutions using BASF’s sprayed concrete and double-bonded waterproofing membrane MASTERSEAL® 345.
One of the event’s highlights was a site visit to a tunnel just outside Trondheim to see the installation of a large application of MASTERSEAL® 345 in action.
The workshop, aimed at designers, engineering consultants and owners within underground construction, addressed a number of aspects of the MASTERSEAL® 345 system, explaining how sprayed concrete and a double-bonded spray-applied waterproofing membrane function together in a monolithic structure, creating a composite waterproof lining.
It then went on to discuss the design issues for the system in different situations, current experience and understanding of the system in cold climate conditions and how the technique is being implemented at the Gevingas rail tunnel project.
International speakers from consulting engineers Mott MacDonald in the UK, Monod-Piguet & Associes from Switzerland, the Norwegian National Rail Administration and iC Consulenten of Austria joined forces with BASF speakers Dr Thomas Kothe and Dr Wolfgang Aldrian to present the two-day event.
Said Karl-Gunnar Holter of MEYCO: “We are delighted with the positive response we received from delegates. This innovative, cost-effective method for tunnel waterproofing has shown significant project savings over the double-shell method on recent projects. We were able to show the advantages of a bonded waterproofing membrane in resolving technical problems that have proved difficult to combat with conventional sheet membranes.”
He explained: “In brief, the bonded membrane prevents migration of water along the concrete–membrane interfaces on either side of the membrane, and the tensile bonding and shear strengths of the combined concrete and membrane give the mechanical behaviour of a composite structure. This means that the primary support lining and the inner final lining act together and can be considered as part of the permanent support structure.
“Both primary lining and secondary lining, together with the bonded membrane, can be designed to offer a permanent, long-term, durable and waterproof tunnel lining.”
The MASTERSEAL® spray-applied system is ideally suited to underground structures with complex geometries, such as lay-by niches, cross passages, turnouts and crossover caverns.