A side-spar cable-stayed bridge may be an otherwise conventional
cable-stayed bridge
A cable-stayed bridge has one or more ''towers'' (or ''pylons''), from which wire rope, cables support the bridge deck. A distinctive feature are the cables or wikt:stay#Etymology 3, stays, which run directly from the tower to the deck, norm ...
, but its cable support does ''not span the roadway'', and is instead
cantilever
A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...
ed from one side. The
Esplanade Riel illustrated is located in
Winnipeg
Winnipeg () is the capital and largest city of the Provinces and territories of Canada, Canadian province of Manitoba. It is centred on the confluence of the Red River of the North, Red and Assiniboine River, Assiniboine rivers. , Winnipeg h ...
,
Manitoba
Manitoba is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population ...
, Canada.
This bridge is intended for pedestrian use only and has a restaurant in its base.
In the example below the cable paths are aligned with the bridge centerline, so that structurally it differs only in the transfer of stresses through the tower to the foundation.
The side-spar principle is not limited to a straight bridge, however. The tower could be offset and the bridge deck wrap around the spar in an arc, e.g.,
Chords Bridge in Jerusalem. Such a bridge would be particularly suited for use in the confines of a canyon, where the road is brought in the upstream direction down one side, crosses a stream, and turns back to a downstream direction on the other side. By placing a large portion of the turn on the bridge, rather than on the approaches, the turn may be made more gentle, allowing faster traffic. This would require more torsional (twisting) rigidity in the roadbed than would a straight bridge. A bridge of this type (supported by a spar), traveling through a much smaller arc, was one of the original proposals for the
eastern span replacement of the San Francisco-Oakland Bay Bridge. Similar bridges, without the spar, could be supported by cables anchored in the canyon walls (where conditions are suitable).
This subtype should not be confused with an asymmetrical single tower cable-stayed bridge, which possesses a single tower on one side of the gap to be crossed (see
Rama VIII Bridge), nor with the
cantilever spar cable-stayed bridge, which has span supporting cables on only one side of the tower along the direction of the roadbed.
Image gallery
Image:SideSparCableStayBridge1.jpg, Esplanade Riel, Winnipeg
Image:WinnepegBridge.jpg, Esplanade Riel, Winnipeg
Image:Esplanderiel.jpg, Esplanade Riel, Winnipeg
Image:Jerusalem Chords Bridge 5.JPG, Chords Bridge, Jerusalem
Image:Jerusalem Chords Bridge, Israel (1).jpg, Chords Bridge, Jerusalem
Image:Jerusalem Chords Bridge.JPG, Chords Bridge, Jerusalem
See also
*
Cantilever spar cable-stayed bridge
References
{{DEFAULTSORT:Side-Spar Cable-Stayed Bridge
Bridges by structural type