Strasky Husty and Partners (Czechia)

The first bridge over Ebro River at its delta was recently constructed, substituting a barge service. The bridge, called “Lo Passador” as homage to the old guiders of the barges, was built in a protected environmental site with great touristic potential, connecting two riverside villages separated by the river. The constructed structure (winner of a design competition) consists of a slender self-anchored suspension bridge of spans 69 + 112 + 69 m, suspended from four parabolic cables through a central web, resembling a sail boat. The web naturally divides the 19,3 m wide cross section into two equal parts, one reserved for vehicles (two lanes) and the other for pedestrians and bicycles, creating a useful path connecting the two villages with amazing views over the river. Slender pseudo-circular piers are used, so that the torsion is directly resisted at the abutments by making use of a torsionally stiff streamlined steel box-girder section. Steel towers were specifically designed shallow in concordance with the shallow fields of the delta surroundings. As a structural consequence, the stress variation in the cables due to live load is minimized, making possible the use of conventional prestressing technology for the cables, which greatly reduces the cost and simplifies the details at the saddles. Selfanchored bridges are usually built over scaffolding, which was not possible over the river. Alternatively, an evolutive construction sequence was used here, including the lifting of a central part from long-stayed cantilevers. The opening of the bridge was eagerly awaited by the citizens of the two villages, and the use of the wide pedestrian path has distinctly changed their relationships.

Abstract This bridge, which won a fib Award for Outstanding Concrete Structures in 2010, connects a newly developed area (Spielberk Office Centre) with an old city district. It is situated in the vicinity of a new international hotel and a prestige business area. Close to the bridge there is an old multi‐span arch bridge with piers in the river. It was evident that any new bridge should also make use of an arch structure, but with a bold span not needing piers in the riverbed, see Fig. 1. Due to poor geotechnical conditions, a traditional arch structure with a large horizontal force to be resisted was considered too expensive. Therefore, a self‐anchored stress ribbon and arch structure was chosen. The smooth curves so characteristic of stress ribbon structures allowed a “soft” connection of the bridge deck at both banks.