The arch bridge replaces the existing road bridge along Ettelbruck Street in Colmar, Luxembourg that crosses the Luxembourg-Troisvierges railroad line. Due to its proximity to the Grand Duke of Luxembourg’s castle, a design was required that would elegantly blend the bridge into its surroundings while also drawing attention to itself. The design by schlaich bergermann partner provides for an arch bridge with a rhombic cross-section.
The cross-sections vary along the bridge axis, depending on the stiffness required to counteract out-of-plane buckling. Due to their slight inward inclination, the arches give the bridge its dynamic appearance. To compensate this inclination and to avoid additional horizontal strengthening of the arches, the hangers are eccentrically attached to the outside of the lateral bridge girders. The lateral girders are designed as trapezoidal hollow steel boxes. Their sharp edges reduce the facing area and emphasize the lightness of the design. The two-lane bridge deck is designed as an orthotropic steel plate.