Side-spar cable-stayed bridge
Encyclopedia
A side-spar cable-stayed bridge may be an otherwise conventional cable-stayed
bridge
but its cable support does not span the roadway, rather being cantilever
ed from one side. The bridge illustrated is located in Winnipeg
, Manitoba
, Canada. This example 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. 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.
Cable-stayed bridge
A cable-stayed bridge is a bridge that consists of one or more columns , with cables supporting the bridge deck....
bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
but its cable support does not span the roadway, rather being cantilever
Cantilever
A cantilever is a beam anchored at only one end. The beam carries the load to the support where it is resisted by moment and shear stress. Cantilever construction allows for overhanging structures without external bracing. Cantilevers can also be constructed with trusses or slabs.This is in...
ed from one side. The bridge illustrated is located in Winnipeg
Winnipeg
Winnipeg is the capital and largest city of Manitoba, Canada, and is the primary municipality of the Winnipeg Capital Region, with more than half of Manitoba's population. It is located near the longitudinal centre of North America, at the confluence of the Red and Assiniboine Rivers .The name...
, Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
, Canada. This example 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. 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
Eastern span replacement of the San Francisco-Oakland Bay Bridge
The eastern span replacement of the San Francisco – Oakland Bay Bridge has been under construction since 2002. Originally scheduled to open in 2007, it is now scheduled to open to traffic in 2013 at an estimated cost of $6.3 billion....
. 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
Rama VIII Bridge
The Rama VIII Bridge in Bangkok, Thailand, officially opened on September 20, 2002. The cable-stayed bridge consists of a single pylon located approximately one-third of the distance from the northwest end of the bridge. Golden suspension cables extend from this pylon to the road surface. The...
), nor with the cantilever spar cable-stayed bridge
Cantilever spar cable-stayed bridge
A cantilever spar cable-stayed bridge is a modern variation of the cable-stayed bridge. This design has been pioneered by the architect Santiago Calatrava. An example of this type is the Puente del Alamillo...
, which has span supporting cables on only one side of the tower along the direction of the roadbed.
See also
- Cantilever spar cable-stayed bridgeCantilever spar cable-stayed bridgeA cantilever spar cable-stayed bridge is a modern variation of the cable-stayed bridge. This design has been pioneered by the architect Santiago Calatrava. An example of this type is the Puente del Alamillo...
- Cable-stayed bridgeCable-stayed bridgeA cable-stayed bridge is a bridge that consists of one or more columns , with cables supporting the bridge deck....
- BridgeBridgeA bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...