Transportation, Geotechnical, Europe, Germany, Government
Accelerating a Major Traffic Route
Geotechnical Monitoring and Safety Measures Enhance City Tunnels in Germany
The trains will soon be running faster through Leipzig station, Europe’s largest terminal train station. Construction of the Leipzig City Tunnel will provide the long-awaited north-south connection, eliminating the need for all trains to travel around the Leipzig city center. This new connection will significantly accelerate the local regional trains and also reduce travel time within the S-train network. With a total of four underground stations, public transportation to the city center in Leipzig will be further optimized.
The €500 million project is considered one of the most challenging geotechnical construction projects of our time. Our geotechnical experts from all over Germany have been involved with this project from its inception, mastering the challenges of the difficult construction conditions due to bedrock formations, lignite deposits and the anthropogenic area. Obstacles such as high-strength sandstone blocks, retaining walls and remaining anchors had to be removed in advance through intricate techniques. We developed the design and a complex safety concept for these specific underground conditions for the deep excavations and the tunnel route.
Especially important was not only the securing of historic 16th Century buildings, but also the undercutting of new buildings without causing any damage; a shield machine undercut a number of buildings with only 1.5 meters of coverage. We applied the compensation grouting process to secure buildings, such as under the Museum of Fine Arts. Here, injections were made in the area of the building’s foundations to stabilize and raise the structure, compensating for the settlement that will occur during the tunnel excavation.
The differing pressure conditions in the various groundwater aquifers and the resulting complex hydraulic flow conditions also made this construction more difficult. Through localized groundwater relaxations and extensive, permanent online groundwater measuring gauges, risks were minimized and results were successful for our clients and for the citizens of the city of Leipzig.