Barbarossatunnel, bypass of Annweiler, B10

The entire length of the tunnel passes through "Oberrotliegende" characterised by relatively changeable sedimentation, ranging from coarse grained sandstones to fine grained sandstones and silt stones. In the portal zones, surface layers mainly comprising slope sand and debris are to be found. Their thicknesses amount to 1.0-1.5 m at the western portal and 0.7-2.0 m at the eastern one. The tunnel gradient is located at least 2 m above the main ground water table. Owing to the slope-parallel inclination of the tunnel section for cut-and-cover, a concrete support for the tunnel cross-section in the form of a gallery was applied. The galleries together with the portals were created by cut-and-cover. For the trenchless excavation, a rising drive from east to west based on the NATM was executed from the pre-cut constructed by cut-and-cover. In solid rock, bore and blasting work was applied to loosen the ground whilst hydraulic excavators were employed in the loose rock section. In a second follow-up phase, the final supporting reinforced concrete vault was placed from east to west following sealing.

• Country: Germany
• Region: Rheinland-Pfalz
• Tunnel utilization: Traffic
• Type of utilization: Road tunnel
• Client: BRD, Straßenverwaltung Rheinland-Pfalz
• Main construction method: Trenchless
• Type of excavation: Drill-and-blast
• Lining: Shotcrete
• No. of tubes: 1
• Tunnel total length: 790 m, incl. 2 x 87 m gallery
• Cross-section: Gallery 75 m², Tunnel 79-94 m²
• Contract Volume: 28.7 mill. plus 5.6 mill. DM furnishing
• Construction start/end: 1991-1995 (4 years)
• Opening: 11.1.1995