Numerous participants once again came to our WBI Center in Weinheim for the 9th Rock Mechanics and Tunnelling Day on 13 June 2024. We are delighted that we were able to create a forum for the presentation and discussion of new findings in our field and for communication. As the speakers submitted their contributions quickly, we are already able to present the conference proceedings here in September.
Damage to the steel armouring has occurred in the 1.3 km long pressure shaft weir of Schluchseewerk AG, which was built in the last century. The article by Robert Render and Daniel Stolz describes the cause and the renovation work. In the meantime, the power plant has been put back into operation.
Martin Wittke and René Sommer examine the methods of classifying fractured rock developed primarily by Scandinavian and Anglo-Saxon experts and their use for determining characteristic values and for design work. They show that the application is associated with great risks and is not effective.
Around 750 tunnels in the Deutsche Bundesbahn network, with a total length of 140 km, are in need of renovation. The construction work required for this will lead to severe restrictions in DB operations, which must be minimised. In their article, Uwe Kneißl and Walter Wittke show that a single-shell construction method using shotcrete is one way of optimising the situation.
Stability analyses of the temporary tunnel face, load assumptions and the tunnelling shield and segments and their design are usually carried out independently of each other when planning mechanical tunnelling. In their article, Patricia Wittke-Gattermann and Bettina Wittke-Schmitt show that in certain cases, especially when driving in pressure-bearing rock, this is not effective. Instead, it is necessary to spatially record the mutual influence of the working face, shield and tubbings.
In the sustainability section, Thomas Chakar deals with the implementation of the Mantelverordnung (Coating Ordinance), the Ersatzbaustoffverordnung (Substitute Building Materials Ordinance) and the Bundes-Bodenschutzverordnung (Federal Soil Protection Ordinance) in the field of road construction administration in Baden-Württemberg. Barbro Hauff explains their implementation using the example of the retrofitting of the Schemelsberg Tunnel with a rescue tunnel. In his contribution, Frank Haehnig impressively demonstrates that special civil engineering in Germany and Europe has been successfully addressing the reduction of emissions for many years. The so-called Carbon Calculator is used to record and document the CO2 footprint of special civil engineering works, and the building ground is viewed and used as a building material wherever possible and sensible.
Sebastian Palt, Patrick Schäfer and Pawan Thapa report on a study by Fichtner GmbH on possible locations for pumped storage power plants in Germany. These will become increasingly important in the course of the expansion of alternative energies to compensate for volatility.
In their contribution to the final topic of the event, Alexander Nolte and Rainer Haschke explain the status of planning for the major project of the Frankfurt long-distance railway tunnel. The construction tasks pending for this project in the inner-city area and in the area of existing track systems, where operations must be maintained, are very demanding. In addition, the Frankfurt building ground places high demands on planning and execution.
The planning and execution of the new U5 underground line in Hamburg, reported on by Stefan Schuster, will also be challenging. The 24 km long line with 23 stops is scheduled to go into operation in 2040.
Kerstin Wulfing and Maximilian Weiß report on the comprehensive data monitoring to be carried out during the construction of the second S-Bahn trunk line.
The contribution by Silke Briebrecher and Dieter Winselmann on the application of the Eurocode in the planning for the Fehmarn Belt crossing shows that different solutions can be arrived at on the basis of the German and Danish National Application Documents, and how this can be dealt with in a cross-border project.
We hope that readers will find the proceedings interesting and informative, and we cordially invite you to Weinheim for the 10th Rock Mechanics and Tunnelling Day on 26 June 2025.
Walter Wittke Martin Wittke Bettina Wittke-Schmitt Patricia Wittke-Gattermann
