Tragwerk der neuen Isabrücke Grünwald

In using the basic elements of the previous arch bridge as well as different materials and new design principles an extraordinary structure was created. The system of the superstructure in total represents a continuous tapered beam over 4 spans on 5 bearing points. It is of composite structure in cross section of 3 parallel positioned steel beams and one reinforced concrete slab over all. The steel beams are split into an upper chord and a lower chord (without webs) with merging areas at the midspans and the ends. The curved lower chords simulate the arch type of the superstructure. In cross-section both chords are of hollowbox. The design of the superstructure including the details of construction-stages is described. Design-problems referring to the prognosticated horizontal movement of the slope of the westbank are additional described.