The special 18-meter length of the Combar bars proved to be advantageous for the construction of the shaft walls, because this allowed for the construction of only one reinforcement cage.
Photo by: Moritz Bernoully
Combar was used as the reinforcement material instead of steel. It is a glass-fiber-reinforced polymer (GRP) specially developed and produced by Schöck, which, unlike steel, can be easily machined.
Photo by: Moritz Bernoully.
In the soft-eye area, reinforcement cages made of Combar were placed throughout a 24-meter area.
Photo by: Moritz Bernoully
The overlapping joints between the individual cages were secured using wire rope grips.
Photo by: Moritz Bernoully
Thanks to its special properties, Schöck Combar is a superior alternative to steel for reinforcement.
Photo by: Schöck Bauteile GmbH
The construction of the 2nd main line between Laim and Leuchtenbergring is to enable faster connections in Munich. The centerpiece is a seven-kilometer tunnel. Diaphragm walls have been built for the "Munich Hauptbahnhof" (Munich Central Station) stop at a depth of 40 meters. The areas for the track crossings and for the intermediate inspection and emergency tunnel were designed as so-called soft eyes with Combar®. Unlike steel reinforcement, Combar® is easy to machine and can be passed through much more easily and efficiently by the tunnel boring machine. This reduces both construction time and costs and increases safety for employees.
The reinforcement cages made of Combar® were placed in an area of 24 meters, which had to be connected to the steel reinforcement cages below and above them on the construction site when they were lowered into the slices. A total of four cage segments were connected to achieve the required length of 56 meters.
The special 18-meter length of Combar® bars was used to construct the shaft walls. In this way, only one reinforcement cage had to be created. Thus overlapping joints between the two cages in the soft-eye area were avoided and the reinforcement density was reduced.
Further information on the project can be found in our report.
Deutsche Bahn
ARGE Tunnel Hauptbahnhof 2. S-Bahn-Stammstrecke München,
Wayss & Freytag Ingenieurbau AG, Bereich Süd
Max Bögl Stiftung & Co. KG
Ed. Züblin AG, Direktion Tunnelbau
SSF Ingenieure AG, Munich
Brühler Stahlhandel GmbH, Brühl