The B3|Südschnellweg is located in Hanover and stretches from the Landwehr roundabout to the overpass of the DB tracks in front of the Seelhorster Kreuz.

There are several structures over a length of approximately 3.8 km. In the course of the project, in addition to widening the road cross section to an RQ 25 (mainly in embankment), the engineering structures are to be renewed.

As part of this contract, the existing water bridges over the Leine flood basin and over the Leine are to be dismantled and rebuilt. The new bridges each consist of two substructures including deep foundations. The construction site is located in a landscape conservation area and a provisionally determined flood zone.

The contract includes, among other things, the construction of the necessary excavation pit structures (also in the water), the pier foundations and abutments including superstructure, the excavation of the excavation pit with earth transport to the staging area and their disposal.

In the course of the expansion, the existing bridge structures over the Leine (length approx. 90 m (old) / 110 m (new)) and Leine flood trough (length approx. 190 m (old) / 245 (new)), each with a one-piece superstructure, will be replaced by new buildings with a standard cross-section RQ 25 and a two-part superstructure. The superstructures of the bridges are prestressed concrete constructions from 1954 (Leine) and 1955 (Leineflutmulde). The prestressing was applied using the Baur-Leonhardt clamping method. For this reason, the dismantling of both water bridges will be carried out with shoring structures. Due to the alignment of the expansion measure close to the existing structure, it will first be necessary to complete the southern sections in a provisional location with subsequent traffic rerouting and only then to dismantle the existing structures. This will be followed by the construction of the northern substructures and finally the transverse displacement of the southern substructures into their final position.