Tunnel Rengershausen
Apart from the undercutting of the A 44 6-lane federal motorway (BAB) in the north and the Main-Weser Railway (MWB) in the south, it was first and foremost, the partly extremely adverse geological conditions, which made the Rengershausen Tunnel one of the trickiest but at the same time, most interesting structures on the DB's new lines. The variegated sandstone rock was split up into individual fault blocks as a result of intensive block tectonics, so that the groundwater penetrated the underground leading to leaching. This, in turn, brought about so-called subrosion depressions, which became filled with tertiary deposits and overlying quaternary clay. In keeping with the geological conditions, layers of variegated sandstone were penetrated in the southern section of the Rengershausen Tunnel until roughly the middle of the tunnel was reached. Some 800 m to the north of the southern portal, the tertiary deposits were encountered. They governed the construction methods applied in the northern section of the tunnel. The area bordering the A 44 to the south was constructed using cut-and-cover on account of the low overburden (12-13 m). Given a maximum depth of 25 m, the excavation including the southern end wall was secured using 1.20 m diameter stiffened bore piles and 3 reinforcing layers. The tricky geological conditions made it necessary to divide the cross-section up into a number of sub-sections. The side walls were first of all driven before the crown was tackled and then the core of the overall cross-section.
- Country: Germany
- Region: Hessen
- Tunnel utilization: Traffic
- Type of utilization: Main-line rail
- Client: Deutsche Bahn AG
- Main construction method: Trenchless
- Type of excavation: Drill-and-blast
- No. of tubes: 1
- Tunnel total length: 1592 m
- Cross-section: 200 m²
- Contract Volume: 65 mill. DM
- Construction start/end: 1988-1991 (3 years)
- Opening: 1991