German TBM manufacturer, Herrenknecht, has won the contract to supply the JV Katzenberg Tunnel with two 11.12m diameter EPBMs that will be used to bore 8.9km of the 9.4km long twin tube Katzenberg rail tunnel in Germany’s Upper Rhine Valley.
The JV, of Ed Züblin, Wayss & Freytag, Marti Tunnelbau and Jäger Bau, will assemble the first machine at the south portal in August this year, an event that will mark the start of construction of what is claimed to be Germany’s longest mechanically excavated tunnel project. The second machine will follow two months later.
The TBMs will bore through weak weathered tertiary sedimentary rocks such as mudstone, siltstone and occasional sandstone. In the southern tube an 800m long stretch of Jara massive chalk will also have to be bored through. The tunnel will be lined with a ring of six precast segments.
The JV was awarded the construction contract in August 2003 by the client, rail operator Deutsche Bahn AG.
During the tendering phase, the client stipulated that both TBM and shotcreting methods should be considered and priced. Following detailed design the TBM method was found to be the cheapest and adopted.
