Isarsteg Nord near Freising, Germany

The engineering office Bergmeister Ingenieure used the RFEM and SHAPE-THIN programs for the structural analysis of the 3D structure.

Structure

The structural design of the bridge was carried out in a sustainable manner. The slim bridge is a rigid, statically indeterminate frame structure. All components, including the foundation and the abutment, are rigidly connected to each other.

The maximum span of the bridge amounts to 55 m (180 ft) and the width to 3.75 m (12.30 ft). The superstructure, the columns, and the stairs consist of keel-shaped, torsionally rigid hollow boxes.

The bridge deck consists of a reinforced concrete flange with a thickness of 15 cm (5.9 in) and a concrete quality of C35/45. It is rigidly connected to the cover plate t = 25 mm (0.98 in) of the steel box section by welded studs. The studs have a distance of 0.5 m (1.64 ft) in the transverse direction and 0.6 m (1.97 ft) in the longitudinal direction.

The bridge was precambered by the deformation components from the self-weight. Under the maximum variable load, the structure deforms by about 112 mm (4.4 in), which corresponds to l/504. The dynamic analysis resulted in a natural frequency of 1.33 Hz for the first mode shape. To ensure user comfort, a vibration damper was arranged.

The aesthetic construction of the Isarsteg was awarded the German Steel Construction Prize in 2016, and 2nd place in the Engineering Prize of the Bavarian Engineers' Association. Moreover, it received a nomination for the German Bridge Engineering Award in 2018.