The Hallandsås Tunnel Project was a major railway infrastructural project in Sweden associated to a long history. It was opened to the public end of 2015. In 2004, the third attempt to complete the construction of the two tunnels started, based on an alternative technical solution involving excavation with a 10.6m diameter dual mode hard rock Mix-Shield TBM, which was a complex machine capable of being operated in open mode, closed mode (slurry) up to 13 bars and to undertake systematic pre-excavation grouting. The large variations in the characteristics of the rock mass, the high water pressure (up to 13 bars) and the presence of long water bearing zones made the ground conditions definitively difficult. The most significant difficulty along the tunnel route was the Mölleback zone, an extensive fault zone, about 320m in length. A part of this fault was subject to an advanced ground freezing operation of 125m in length in order to permit TBM excavation, the remaining part being treated by conventional cement grouting.
Francois Dudouit has over 33 years of construction experience, gained on major railway underground projects in France, Denmark, Hong Kong, Nederland and Sweden. His experience includes TBM excavation in challenging soft ground and hard rock, with pressure up to 13 bars. Between 2003 and 2012, he was responsible for the construction on the Hallandsås Tunnel Project. He is presently Project Director of Link Alliance for City Rail Link Contract C3.