The Stockholm Bypass - Design and execution of grouting works - Pre-excavation grouting by means of rock fissure grouting with cementitious grouts

The E4 Stockholm Bypass is a new route for the European highway (E4) past the Swedish capital Stockholm. The bypass will connect the southern and northern parts of Stockholm. To reduce the impact on the surroundings, 18 km of the total of 21 km of the Stockholm Bypass are being constructed in tunnels. The Bypass will be one of the longest road tunnels in the world, with a construction cost of 3.1 billion Euro (2009 prices).
The challenges have been many, for example how to evaluate the hydraulic rock mass properties for such a vast tunnel stretch and then find the most suitable grouting design, the contractor's ability to deliver proper grout properties and suitable grouting equipment, the time and resources needed for QA/QC of the grouting works and the need for adaption of the grouting works to true geological conditions. Not to mention the complexity of monitoring water ingress during construction for the Client to show that the sealing demands are being met according to the environmental permits for water works operations. The Stockholm Bypass is by far the largest rock fissure grouting operation undertaken for road tunnels in Swedish history.