New Semmering Base Tunnel - the current state of tunnel design taking the newest investigation results into account

As result of the two-year route selection process, the southernmost variant Pfaffensattel was chosen in April 2008 as the best variant for the New Semmering Base Tunnel, which run from Gloggnitz to the Mürzzuschlag-Langenwang area, and the route has since been optimised for design through a detailed programme of investigations. As a result of this, the final route of the tunnel was fixed in autumn 2009. All design work for the partially concentrated approvals process are now based on this route.
This article is concerned with the essential technical tunnel construction aspects of the design to be handed in for approval, above all the construction concept and the procedure for geotechnical design to be used as a basis. At the time of writing this article, the final evaluation of the geomechanical and hydrogeological investigations and the geotechnical design are still underway.