Footbridge over the River Mur Murau

The bridge was originally built for a major timber construction exhibition. In contrast to normal bridges, the footbridge for pedestrians and cyclists connects four different starting points at just as many different levels. The actual junction is a post-tensioned timber girder with a large free span that connects the railway directly with the town. Various access ways open up, each with its own arm, like split-off pieces of the timber girder lying scattered on the ground. We treated the wood construction of the load-bearing structure as a monolithic body—almost like a monocoque structure—whose lower and upper flange reinforcements carry the roof and floor of the bridge. In immediate proximity to the engineer’s load-bearing structure plan, we created the actual bridge space through manipulation of its static elements: that is, slabs and plates.

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In this, the core of the idea was shaped by the single-span Vierendeel girder. This novel construction in wood provided the base for the spatial interpretation of the footbridge. The Vierendeel girder allows a huge window to open precisely at the site of the greatest bending moments in the middle of the river. There, the four entry spaces, which are separated by shear walls, merge to the central space of the bridge. Like a massive picture window, the opening offers a view into the impressive landscape. The sideways shifted shear walls align with the horizontal surfaces of the floor and the roof of the space through their diagonal placement. They are reminiscent of early modernist minimalist spatial experiments. 

Truly innovative about this bridge was the integrated construction, developed together with Jürg Conzett and Kaufmann Holzbau in Vorarlberg. The prestressing of the lower flange as well as the production of very large, timber carrying parts presented challenges. In this bridge, the principle of glueing and pressing arises in different scales: first by the industrialized process of forming glue-laminated timber beams out of wooden boards. As many as five of these beams are assembled by glueing within a pneumatic compression press to the lower and upper chords: for the shear walls, they are pressed by a dense nailing. Finally, the chords were delivered to the building site in two pieces each and glued with an epoxy resin. There, the necessary pressure was applied by the structure’s dead weight (upper chord) or by a post-tensioned cable of 409 tons (lower chord). This procedure enabled the production of a wooden bridge as a spatial system solely from the structural parts.

Location: Murau (A)

Competition: 1993

Project: 1993–1995

Realization: 1995

Client: Steiermärkische Landesregierung, Graz (A)

Meili, Peter Architekten: Marcel Meili, Markus Peter

Astrid Staufer

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ENGINEERS: Branger & Conzett Engineers, Chur

TIMBER CONSTRUCTION: Kaufmann Holzbauwerk, Reuthe (A)

publications

«Architecture in Austria, A Survey Of The 20. Century»
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Birkhäuser Publishers | ACTAR, Basel/Barcelona 1999

«5th Mies van der Rohe Pavilion Award for European Architecture, 1997»
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Katalog der nominierten Bauwerke, Milano 1997

«Novy most. pro starobyle mesto»
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Architekt, Nr. 11/1996

«Bridge of Murau»
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Architecture and Urbanism, Nr. 06/1996

«Estancia sobre el rió. Puente sobre il rió Mur, Murau»
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Arquitectura Viva, Nr. 48/1996

«Die Brücke als Horizont»
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Daidalos, Nr. 58/1995

«Raumbrücke»
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Werk, Bauen + Wohnen, Nr. 12/1995

«Zum Stand der Dinge»
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archithese, Nr. 5/1995

cross section of bridge with footbridge

view city side

Structural cross section and view with laminated wood boom with post-tensioning cable, lower construction of roof and pathway

construction axonometry with dismantled shear walls

Bending moment and the course of the lateral force in the main support

strain isometry of the main support

Bridge entry on the city side with bicycle path and steps leading upward

Veduta of the bridge from Reichenau (Graubünden). Image from Angelo Maggi, Nicola Navone, JOHN SOANE E I PONTI IN LEGNO SVIZZERI, Mendrisio 2002, p.122.

Installation process of the bridge in July 1995, finished state

Connection of footbridge to the main bridge

Bridge space, direction train station

view from the city side

«Window» in the middle of the bridge

View of the city side

Working model of the first bridge position

Bottom boom with channel for post-tensioning cable

Bridge from Stowe (1744), Sodbach Bridge (1867), Neckarwehr Besigheim (1910)

The design treats the bridge as a sculpturally formed, homogeneous, and spacecreating
piece of wood.