As part of this construction project the Fildertunnel forms a twin bore rail tunnel where mechanized excavation started in 2014 utilising a Herrenknecht Multi-mode TBM with a diameter of 10.82 m.
The twin bore comprised the tunnelling of two 9.5 km long tunnels with included curves of minimum radius 2,300 m.
Work first started on the Fildertunnel in November 2014. Tunnelling was completed in four sections with the first breakthrough occurring in November 2015, the second in July 2017, the third in July 2018 and the final breakthrough occurring in September 2019.
TBM guidance throughout the various tunnelling sections of the project was provided and supported by VMT, which has its offices close to the project site. The VMT navigation used for the project was the TUnIS Navigation TBMLaser system. Based on a total station and a target unit installed within the TBM shield, it determines the current advance position. Even for segment machines using a small or limited laser window, the machine position is continuously calculated during short-term interruptions. TUnIS Navigation TBMLaser offers high reliability since it provides temporary navigation through the thrust cylinders with the aid of the newly developed TUnIS Track Assistant system.
An IRIS system (now known as VDMS – VMT Data Management System) was also utilised on the project. IRIS/VDMS processes and correlates data from a variety of different sources, analyses them and displays them in user-friendly form so that they can be made available to project managers on site or worldwide in a wide range of output forms. The system ensures full information and transparency and supports the efficient control of both the TBM and also many other operating processes within tunnelling projects. As a web-based system, the system can be operated easily from any internet browser on site or as in this case the system can be located locally, solely on site.
The jobsite experienced few problems however at one stage the TBM was found to be drifting. In association with the tunnelling engineers it was decided to change the setting for the support ring sequencing to compensate for this behaviour, in the calculation of the ring orientation.
At a Glance Fact Sheet: