The Strindheim tunnel

The 2.5 km long Strindheim tunnel will run from Nyhavna to Strindheim in Trondheim. This complex tunnel project will be built under challenging ground conditions due to minimal rock thickness and rock overburden in one of the major crossings. The preparations and investigations prior to the field work have therefore been very thorough.

The Norwegian Road Administration plans to open to traffic the new Strindheim tunnel in Trondheim as part of the new E6 in Stjørdal in the spring of 2014. The four-lane tunnel will end with a complex intersection at three levels. Two kilometres of the tunnel will be constructed in rock, while the rest will be a cut-and-cover concrete tunnel through soil.

The zoning and regulation plan in the area impose many strict requirements for the project, resulting in minimal rock thickness and rock overburden for the tunnel system and crossings. In particular, emphasis needs to be placed on how to construct and secure rigid and robust ramp tunnels that come in very close to the main tunnels.

In cooperation with Reinertsen, NGI developed construction plans and material for contract bidding on assignment from the Norwegian Road Administration. The contractor SKANSKA won the bidding process and construction work for the tunnel started in January 2010 and will be completed by 2013.

NGI's responsibility in the project has been to provide engineering geology expertise and do the design for the rock tunnel and geotechnical design of the support structures in and adjacent to the Strindheim crossing. In addition, NGI evaluated the settlement aspects related to  injection required for the tunnel construction work.

The Strindheim tunnel (dotted yellow line).