The winning design “un solo arco” in the competition for the construction of the St. Luzi bridge in Chur was developed in close cooperation with Conzett Bronzini Partner AG, Tuffli & Partner AG and Vogt Landschaftsarchitekten. It convinced the jury with its slim elegance, its considerate integration into the townscape and landscape, and its high standards of sustainability. The bridge crossing the valley is to connect Julierstrasse with Schanfiggerstrasse, which opens up the municipality of Arosa, and thus relieve the city center.
The structure consists of a filigree steel arch and a composite deck. The roadway is elevated on slanted supports. The steel girder combines with the arch at the key-section over 72 m to form a single box. The entire steel structure is made of weathering structural steel, without any coating materials.
The fixed arch is anchored on both sides in the rock and is additionally stabilized by the fixed roadway girder on the Arosa side. There are movable bearings on the abutment side towards Chur.
In order to avoid lifting loads at the crown bearings, the end span is designed as a hinged, transversely fixed prestressed concrete superstructure.
The arch will be built in the classic cantilever construction method, but without a pylon suspension. After the two cantilevers have been constructed, the arch’s crown section will be lifted in completely from the valley floor. The roadway cross-section will then be completed with a fully doweled roadway plate after the steel arch has been constructed, to form a composite cross-section.
