Miltenberg-Großheubach Tunnel

It was necessary to realign the 2309 regional highway to relieve congestion when passing through the localities of Miltenberg and Bürgstadt. The Staatliche Bauamt Aschaffenburg awarded the 4.8 km long new route for the bypass within the scope of a Public Private Partnership (PPP) model to a general contractor. Towards this end on the basis of a functional construction contract the building, maintenance for a 25-year period as well as the private pre-financing of the total section and all related engineering structures were commissioned. The bypass cuts through the outskirts of a neighbouring natural stone plant, which poses a danger. To protect road traffic from the effects of blasting operations in the quarry belonging to the plant the Miltenberg- Großheubach Tunnel was set up at this point. Work started in excavating the roughly 400 m long and up to 18 m deep pit for the tunnel to be produced by cut-and-cover in January 2006. Some 40,000 m³ of rock material was removed using heavy excavators by conventional means and broken with rock bits. The excavated material was then reintegrated within the bypass section for building embankments and replacing soil using heavy rolling equipment. Work on the first tunnel section began at the east tunnel portal (at the slope leading to the River Main connecting with the new Main bridge) while the rock excavation operations were still taking place. 10 m sections of the tunnel frame were shuttered, reinforced and concreted using formwork cars in a weekly cycle. In March 2007 the 350 m long tunnel was finished in its carcass state. Subsequently the up to 7 m high covering for the tunnel was installed. The single-carriageway Miltenberg- Großheubach Tunnel is 350 m long. The tunnel cross-section's clear width amounts to 9.50 m, the clear height 4.50 m. The carriageway is 7.50 m wide. The gradient falls continuously from the west to the east portal at approx. 2.7 %. Operational equipment such as lighting, self-illuminating marking elements, evacuation path identification, a tunnel radio system, a fire alarm system with back-up visibility measurement units and emergency call pillars with fire extinguishers as well as extinguishing water facilities have been installed at the tunnel portals. An emergency halt and breakdown bay is set up in front of each portal. Traffic technical installations with lane change and variable message signs are set up in the portal access areas to safeguard the flow of traffic. Great attention was paid during the tendering stage to ensure that the tunnel portals looked good architecturally.

• Country: Germany
• Region: Bavaria/western north Bavaria at the foot of the Spessart
• Tunnel utilization: Traffic
• Type of utilization: Road Tunnel
• Client: Free State of Bavaria
• Consulting Engineer: Staatliches Bauamt Aschaffenburg, Obermeyer Planen+ Beraten GmbH
• Contractor: Max Bögl, Neumarkt i. d. Opf.
• Main construction method: Open
• Type of excavation: Cut-and-cover
• No. of tubes: 1
• Tunnel total length: 350 m
• Contract Volume: 3.8 mill. Euro (roughwork), 1.4 mill. Euro (operating technology)
• Construction start/end: 2005-2007 (24 months)
• Opening: December 2007