New highway BAB 44 Kassel - Herleshausen, VKE32 Tunnel Küchen.
The contract comprises a 4.3 km long stretch consisting of the twin-tube Küchen tunnel (south tube: 1'333 m / north tube: 1'372 m), earth works and road construction Küchen. Due to the tunnel length, 5 cross connections and 2 emergency breakdown bays are planned.

The tunnel is to be built up as a double lined vault construction: with a shotcrete- and a cast in place concrete inner lining. The site installations are located near a residential area. The cross section is of 100 m² and 135 m² in the emergency niches. The excavation is performed with the D&B method and crosses under the Küchen location with a minimum overburden of 5.5 m. The construction works started in December 2012, including amongst other, the excavation of the pre-cut of the Küchen tunnel.

• Open construction pit east 2 x 20 m
• Shotcreted portal east 42 m and 72 m
• Rock tunnel 1 x 1‘259 m

1 x 1‘198 m

• Shotcreted portal west 32 m and 23 m
• Open construction pit west 2 x 20 m
• Excavation volumes 260‘000 m³

Concrete-/shotcrete volume ca. 140‘000 m³

• Reinforcement steel ca. 14‘600 t
• Construction method

sprayed concrete lining excavation method (top heading, bench and invert excavation)

• Minimum overburden 5.5 m
• Maximum overburden 47 m

The Tunnel Küchen lies along its entire length in sedimentary red sandstone formations.
The tunnel has an overburden in a range of 5.5 to
47 meters. Due to the proximity of the groundwater level, the entire structure is protected by a waterproofing membrane.