Waterproofing the Thames Tideway Tunnel

Why Sikaplan sheet membrane is the trusted choice for tunnel waterproofing

Sika’s sheet and liquid membranes are used globally to waterproof road, rail, metro and water/sewer tunnels.

With an impeccable track record, Sikaplan® sheet membrane is a preferred solution for tunnel designers, not least because it has a design life in excess of 120 years and the ability to compartmentalise the system to enable effective repairs.

Only ever installed by trained applicators, the assurance of quality is essential to the main contractor, joint ventures and the client alike.

Sika’s role in the Thames Tideway Tunnel project

The Thames Tideway Tunnel will be a 25km tunnel running mostly under the tidal section of the River Thames through central London to capture, store and convey almost all the raw sewage and rainwater that currently overflows into the river in storm conditions.

Due for completion in 2024, this £4.2 billion super sewer is split into three sections, West, Central and East.

A broad suite of products and solutions is being used to compliment the main Sikaplan® sheet membrane, including the installation of waterbars, waterstops and injection hoses.  Sika also offers admixtures for the back-fill grout which is placed in the annulus gap behind the concrete segments and the cut of the tunnel. This creates an increased level of protection from water ingress.

Going the extra mile

Across the Thames Tideway project Sika has been proactive in speaking to a number of the 24 individual sites along the route, offering toolbox talks and site training, bespoke details and waterproofing advice to aid with the performance of all concerned.

Thousands of metres of SikaFuko® injection hose and resin, combined with Sika® elastomer waterbars, have also been supplied for the project, with the latter providing a unique solution due to the depth and chemical resistance properties of the ground material.Watertight reassurance

Tunnel Boring Machines (TBM) achieve waterproofing as the machine breaks through ground by placing gaskets along the concrete tunnel.  If and where these fail Sika can offer various injection solutions.  Twin-bored tunnels also present unique challenges that we specialise in resolving.  Side-by-side tunnels feature cross passages which are usually constructed with a sprayed concrete primary lining, followed by Sikaplan® membrane and a cast secondary lining . Linking the membrane to the back of the tunnel segments can be a vulnerable detail, but Sika has solutions that prevents this being a cause for concern.Sika is always on hand to offer a full solution of admixtures, fibres for cast, sprayed and precast tunnel concrete designed specifically for tunnelling applications.