Zürich, Switzerland

Studienauftrag Ausbau Bahnhof Hardbrücke Zürich

True Grid

Dürig AG, Pöyry Infra AG, Klaus Zweibrücken

The project is determined by the extreme conditions of the site through its location (at the border of the vast field of tracks of Zurich main Station, with different levels and geometries of the existing station), its urban scale, the traffic node (interchange with trains, trams, buses, cars, passengers) and the very restrictive secondary conditions (restricting possibilities of structural supports due to the necessity of unobstructed rail tracks, narrow platforms, construction process). It was asked for a clarifying resolution to this complex situation and at the same time for an adequate symbol with landmark quality to underline the importance of the still emerging new quarter of Zurich West.

The new station is organized on two levels. The platforms on the lower level are completely covered with a vast deck structure which is only interrupted and accentuated by punctuating stairs and lifts to the platforms. The uncovered public deck on the level of the road traffic bridge serves as a vast distributor for commuters and at the same time as a public square where also commercial facilities are sprinkled in. The deck is, as a platform, becoming an enlarged part of the new area of the city itself, offering new qualities and an unknown and unexpected view of Zurich over its vast field of railway tracks. The idea is to create a public space, not a building.

The site is marked by two strong geometries: first of the linear railway tracks running west-east and secondly by the concrete Hardbrücke (bridge for road traffic) running north-south which crosses the tracks at an almost perpendicular angle. A criss-crossed, in appearance heavy load-bearing structure takes up these two main directions, carries the deck from above and establishes virtually a construction free zone at platform level. Thus, platform and deck are structurally separated and independent from each other. This ensures maximum flexibility of space, also for future needs by a minimal structural support at ground level of the railway tracks.

The primary structure consists of twelve columns which carry at a wide span six girders in cross section and four overlaid beams in longitudinal direction. Because the road bridge is crossing the deck at the same level of height, the deck is split into two decks which are separately suspended from the load-bearing structure at each side of the road bridge. The chosen construction made out of steel beams allows a parallel construction which is inline with the direction of the trains. For the protection of the structure and for architectural expression, the beams are covered with aluminum panels, which underlines the landmark quality of the construction.

Each platform of the station is reached with four stairs allowing a good and comfortable distribution of the passengers even at rush hour. The generous deck structure also offers ample space for the bus and tram stops on bridge level as for additional uses like a kiosk, bars or bicycle shelters. The simple and uncovered structure gives the user the feeling of transparency and allows views to the surrounding neighbourhood, anchoring the new station in the area.

The answer to a complex, difficult, cramped and unattractive site is a in its architectural language extremely simple, direct and generous intervention creating an open, functional and dynamic urban square with landmark qualities, not only for this particular area of the city, but for the city of Zurich as a whole.

Europaconcorsi Beta

Studienauftrag Ausbau Bahnhof Hardbrücke Zürich