Tunnel Herfatz, BAB 96

The tunnel passes through glacial moraine deposits of the Voralpenland. Stiff-plastic or semi-solid glacial loam is to be found below the surface layer comprising fine sandy, weak gravelly or gravelly silts between 0.8 and 2.5 m thick. Ground moraine is located beneath this. As a result of the hydrological situation, it was predicted that a groundwater current would intersect the tunnel from north to south. In order to avoid interrupting the suspected groundwater current, a system of drains was set up at 15 m gaps, which extended to the ground surface. The tunnel was executed by cut-and-cover. The excavation did not have to be secured. The construction trench was escarped. In order to achieve a favourable supporting behaviour, the tunnel cross-section was selected along the lines of mining cross-sections.

• Excavated soil: approx. 280,000 m³
• Reinforced concrete: approx. 3,000t
• Concrete: approx. 30,000 m³
• Sealing: 33,000 m²

• Country: Germany
• Region: Bayern
• Tunnel utilization: Traffic
• Type of utilization: Road tunnel
• Client: Bundesrepublik Deutschland
• Main construction method: Open
• Type of excavation: Cut-and-cover
• No. of tubes: 2
• Tunnel total length: 440 m
• Contract Volume: 22.2 Mio. DM
• Construction start/end: 1988 till 1990
• Opening: 30. 9. 1990