The Sunniberg Bridge is a curved multi-span extradosed road bridge with low outward-flaring pylons above the roadway edges, designed by the renowned Swiss engineer

Christian Menn Christian Menn (March 3, 1927 – July 16, 2018) was a renowned Swiss civil engineer and bridge designer. He was involved in the construction of around 100 bridges worldwide, but the focus of his work was in eastern Switzerland, especially in can ...

and completed 1998. It carries the Klosters bypass road 28 across the

Landquart River The Landquart is a river of Switzerland in the canton of Grisons and a right tributary of the Alpine Rhine. It is formed by the confluence of the two mountain streams, ''Vereinabach'' and '' Verstanclabach'', both originating from glaciers in t ...

near the village of

Klosters Klosters is a Swiss village in the Prättigau, politically part of the municipality of Klosters-Serneus, which belongs to the political district Prättigau/Davos in the canton of Graubünden. In 2021, the municipality shortened its name to Kl ...

in the canton of

Grisons The Grisons () or Graubünden,Names include: *german: (Kanton) Graubünden ; * Romansh: ** rm, label= Sursilvan, (Cantun) Grischun ** rm, label=Vallader, (Chantun) Grischun ** rm, label= Puter, (Chantun) Grischun ** rm, label=Surmiran, (Cant ...

in eastern

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

. It is notable because of its innovative design and aesthetically pleasing appearance sensitive to its surroundings.

Design

The bridge was designed by

(conceptual design) together with Dialma Jakob Baenziger (final design) as a challenge of integrating the structural form of a curved multi-span

extradosed bridge An extradosed bridge employs a structure that combines the main elements of both a prestressed box girder bridge and a cable-stayed bridge. The name comes from the word ''extrados'', the exterior or upper curve of an arch, and refers to how the "s ...

into the larger rural Alpine landscape, given the prominent location of the bridge in the Landquart valley, "but with a certain elegance". Sunnibergbrücke 03

The Klosters bypass highway crosses the

valley on a long curving road bridge (horizontal radius of curvature about 500m) at a height of between 50 and 60m above the valley floor. Four slender H-shape piers rise up from the valley floor (8.80m × 4.25m at the base), like the tall trees nearby. Proceeding upwards, the arms of the tall piers/pylons flare out to subtend and sustain the wide curved and banked deck, nestling the roadway in their arms. The bridge received the

Outstanding Structure Award The Outstanding Structure Award is an award presented by the International Association for Bridge and Structural Engineering to the Engineer, Architect, Contractor, and the Owner in recognition of ''the most remarkable, innovative, creative or othe ...

in 2001 for being "a delicate expression of structural art responding to a sensitive landscape.". Sunniberg Bridge elevation with geology

Construction

Construction started Spring 1996, by Batigroup AG and Vetsch AG, starting at the north end with pier P1, the pier closest to the Landquart to Klosters road. Once the piers were completed, the deck were erected using the balanced cantilever method. The bridge was completed ahead of schedule in Fall 1998.Structurae database: Sunniberg Bridge
/ref> Sunnibergbruecke nord

The completed bridge was not opened for traffic because the Gotschna Tunnel, to which the south end of the bridge was connected, was still under construction. Instead, it was used only to access the excavation sites for the tunnel in the interim, until 2005 when the Klosters bypass, including both the bridge and the tunnel, was opened for traffic in a ceremony with

Prince Charles Charles III (Charles Philip Arthur George; born 14 November 1948) is King of the United Kingdom and the 14 other Commonwealth realms. He was the longest-serving heir apparent and Prince of Wales and, at age 73, became the oldest person to ...

, a frequent visitor to Klosters.

Critique

In the 2009 International Award of Merit to engineer/designer Christian Menn, his Sunniberg Bridge, along with his

Ganter Bridge Ganter Bridge is a multi-span reinforced-concrete road bridge that is the second longest spanning bridge in Switzerland after Poya Bridge. It spans the Ganter River valley and is located along the Simplon Pass road about south of Brig in the c ...

, his

Leonard P. Zakim Bunker Hill Memorial Bridge The Leonard P. Zakim () Bunker Hill Memorial Bridge (also known as “The Zakim”) is a cable-stayed bridge completed in 2003 across the Charles River in Boston, Massachusetts. It is a replacement for the Charlestown High Bridge, an older trus ...

as well as others, were singled out as being renown "worldwide for their structural beauty, economic efficiency, technical innovation, and for simply being structural engineering oeuvres of art." From a 2015 Structural Engineering International retrospective, "The Impact of the Sunniberg Bridge on Structural Engineering, Switzerland", the following points can be made about the impact of the Sunniberg Bridge: * It was a favorite among structural engineers, ranked no. 5 among most favorite structure published from 1991 to 2000. * It helped establish "extradosed bridge" as a new and distinct bridge type. * It is a ''curved'' multi-span extradosed road bridge, which is uncommon. * It is an ''integral'' bridge, i.e., it has neither joints nor bearings at their ends, but the girder is rigidly connected to the abutments; thus it is easier to maintain. * It shows that concrete can be used to build slender structures with elegance.

Gallery

The four piers/pylons of Sunniberg Bridge are numbered from north to south as P1 to P4. File:Sunnibergbruecke unten.jpg, From river level looking north: pylons P1 and P2 (right) File:Sunnibergbruecke sued.jpg, From south abutment looking north: pylons P2, P3, and P4 (right) File:Sunnibergbrücke 01.JPG, From south abutment looking north: pylons P1 (left), P2, P3, and P4 (closest) File:Sunnibergbrücke 02.JPG, From south abutment looking north: P4 cable anchors on roadway east edge File:Sunnibergbruecke nordwest.jpg, From north abutment looking south east: pylons P1 (closest), P2, P3, and P4 File:Klosters-Sunnibergbruecke-view from the raetische Bahn-01.jpg, From

train In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...

east of the north abutment looking south: pylons P2 and P1 (center) File:Sunnibergbrücke über die Landquart, Klosters-Serneus GR 20190830-jag9889.jpg, From valley level looking west: pylons P3 (left), P2, and P1 File:Sunnibergbrücke Huefte.jpg, From valley level looking east: pylon P3

References

External links