The Hirschhagen Highway Tunnel (BAB 44) in Germany: Pre-Support in Extremely Difficult and Inhomogeneous Ground Conditions

摘要

The 2nd longest German Tunnel Hischhagen is under construction since 2013. Since the beginning more than 50,000 meters of AT- Pipe Umbrella pipes with Squeezed Connection were installed and the following tunnel excavation safely executed. This successful application demonstrates that the newly developed Squeezed Connection in combination with the AT-Automation Unit improve both the structural behavior as well as the construction performance of pipe umbrella support. It ensures quicker overall installation times by a higher grade of mechanization, higher safety for the involved workforce by less rotating parts and less heavier pieces to handle and last but not least a high cost efficiency of the installed pipes as support element.