Lowering of Rheinuferstraße, Dusseldorf
The geology consists of 3 layers superimposed on each other:
- 3 - 5m fill.
- quaternary layer with gravel and sands some 15 m thick, in which the groundwater current runs from the city to the Rhine.
- beneath the quaternary, there is a watertight tertiary layer comprising fine sands.
The tunnel is located on the bank of the Rhine and in the groundwater current from the city to the river. As a result, special ecological considerations had to be taken into account during construction as well as after conclusion of the project, for instance, the groundwater current was not to be negatively influenced if at all possible. The tunnelling site was located in a densely built-up area with busy road traffic (which has since been re-routed through the tunnel). As a result, far-reaching measures for diverting the traffic and reducing the noise and other negative effects for local residents had to be undertaken. The tunnel was executed via cut-and-cover. Curtain walls were first of all set up to secure the excavation. In order to ensure that the groundwater current was not hampered, the excavation supports were only set in the watertight tertiary layer in cases of exception. The foundations of buildings, which were located in the immediate vicinity of the curtain walls, were secured against settlements via high-pressure grouting. Several construction methods were used to complete the tunnel:
- top cover method, in the case of which the top of the tunnel was used to strengthen the excavation.
- in excavations with groundwater, the lower tunnel tube was executed under compressed air following the completion of the upper tunnel tube.
On account of the special location of the tunnel surrounded by buildings and its length, wind channel tests were also carried out apart from theoretical calculations to solve problems relating to waste air. The tunnel was furnished with a total of 72 jet fans.
- Country: Germany
- Region: Nordhrein-Westfalen
- Tunnel utilization: Traffic
- Type of utilization: Road tunnel
- Client: Landeshauptstadt Düsseldorf
- Main construction method: Open
- Type of excavation: Cut-and-cover
- No. of tubes: 1
- Tunnel total length: 1928 m
- Cross-section: 9.70 x 4.80 m²
- Contract Volume: 543 Mio. DM
- Construction start/end: 3 years and 9 months
- Opening: 15th December 1993