Simple suspension bridge
Descendant |
|
---|---|
Carries | Pedestrians, livestock |
Span range | short to medium |
Material | Rope (fiber), chain, steel wire rope; appropriate decking material |
Movable | No |
Design effort | low |
Falsework required | No |
A simple suspension bridge (also rope bridge, swing bridge (in New Zealand), suspended bridge, hanging bridge and catenary bridge) is a primitive type of bridge in which the deck of the bridge lies on two parallel load-bearing cables that are anchored at either end. They have no towers or piers. The cables follow a shallow downward catenary arc which moves in response to dynamic loads on the bridge deck.
The arc of the deck and its large movement under load make such bridges unsuitable for vehicular traffic. Simple suspension bridges are restricted in their use to foot traffic. For safety, they are built with stout handrail cables, supported on short piers at each end, and running parallel to the load-bearing cables. Sometime these may be the primary load-bearing element, with the deck suspended below. Simple suspension bridges are considered the most efficient and sustainable design in rural regions, especially for river crossings that lie in non-floodplain topography such as gorges.
Comparison to other types
In some contexts the term "simple suspension bridge" refers not to this type of bridge but rather to a
The differences between these two curves were a question of importance in the 17th century, worked on by
A stressed ribbon bridge also has one or more catenary curves and a deck laid on the main cables. Unlike a simple suspension bridge however, a stressed ribbon bridge has a stiff deck, usually due to the addition of compression elements (concrete slabs) laid over the main cables. This stiffness allows the bridge to be much heavier, wider, and more stable.
History
The simple suspension bridge is the oldest known type of
The earliest reference to suspension bridges appear in
In South America, Inca rope bridges predate the arrival of the Spanish in the Andes in the 16th century. The oldest known suspension bridge, reported from ruins,[clarification needed] dates from the 7th century in Central America (see Maya Bridge at Yaxchilan).
Simple suspension bridges using
Development of wire cable
Materials
This type of bridge is known as a rope bridge due to its historical construction from rope. Inca rope bridges still are formed from native materials, chiefly rope, in some areas of South America. These rope bridges must be renewed periodically owing to the limited lifetime of the materials, and rope components are made by families as contributions to a community endeavor.
Simple suspension bridges, for use by pedestrians and livestock, are still constructed, based on the ancient Inca rope bridge but using wire rope and sometimes steel or aluminium grid decking, rather than wood.
In modern bridges, materials used instead of (fiber) rope include wire rope, chain, and special-purpose articulated steel beams.
Living bridges
In the northeast Indian state of
In the Iya Valley of Japan, bridges have been constructed using wisteria vines. To build such a bridge, these vines were planted on opposite sides of a river and woven together when they grew long enough to span the gap. The addition of planks produced a serviceable bridge.[16][17]
Design
The arc of the bridge deck varies between a catenary and a parabola, depending on the weight of the bridge itself versus the load it carries.[citation needed]
The very lightest bridges of this type consist of a single footrope and nothing more. These are
In some cases, such as the Capilano Suspension Bridge, the primary supports form the handrails with the deck suspended below them. This makes for more motion side-to-side in the deck than when the primary supports are at deck level, but less motion in the handrails.
Disadvantages connected with simple suspension bridges are very great. The location of the deck is limited, massive anchorages and piers generally are required, and loading produces transient deformation of the deck.[18] Solutions to these problems led to a wide variety of methods of stiffening the deck,[18][19] resulting in several other types of suspension bridge. These include a stressed ribbon bridge, which is closely related to a simple suspension bridge but has a stiffened deck suitable for vehicle traffic.
A very light bridge, constructed with cables under high tension, may approach a
The bridge may be stiffened by the addition of cables that do not bear the primary structural or live loads and so may be relatively light. These also add stability in wind. An example is the 220-meter-long (720 ft) bridge across the river Drac at Lac de Monteynard-Avignonet: this bridge has stabilizing cables below and to the side of the deck.
To reduce twisting motion in response to users a bridge may employ vertical drop cables from each side at the center of the bridge, anchored to the ground below.
Use
The lightest of these bridges, without decking, are suitable for use only by pedestrians. Light bridges with decking, and sufficient tension that crossing the bridge does not approach climbing, may be used also by
Simple suspension bridges have applications in outdoor recreation. They are a popular choice for tree-top trails[20] and, where the terrain is suitable, for stream crossings.[21] They may be designed without stabilizing so that the free movement of the bridge provides a more interesting experience for the user.[21]
In French, a rudimentary simple suspension bridge is known by one of three names, depending on its form: pont himalayen ("Himalayan bridge": a single footrope and handrails on both sides, usually without a deck); pont de singe ("monkey bridge: a footrope with overhead rope); and tyrolienne ("Tyrolean": a zip-line).[22] Zip-lines can be traversed by hanging below, or walked (by individuals with exceptional balance). A more developed version of the pont himalayen, provided with a deck between a pair of main cables, is known as a passerelle himalayenne (French, "Himalayan footbridge").[23] Examples of this type include two bridges at Lac de Monteynard-Avignonet in the French Alps; these bridges are exceptionally long, for bridges of this type.
Notable bridges
Notable simple suspension bridges include:
Name | Span length
|
Year built |
---|---|---|
Capilano Suspension Bridge | 140 metres (460 ft) | 1889 |
Arroyo Cangrejillo Pipeline Bridge | 337 metres (1,106 ft) | 1998[24] |
Lac de Monteynard-Avignonet Drac bridge | 220 metres (720 ft) | 2007 |
Carrick-a-Rede Rope Bridge | 20 metres (66 ft) | rebuilt 2008 |
Ponte tibetano Cesana-Claviere
|
478 metres (1,568 ft) | 2006[25] |
Ponte nel Cielo | 234 metres (768 ft) | 2018[26] |
Charles Kuonen Suspension Bridge | 494 metres (1,621 ft) | 2017[27] |
Gandaki Golden Footbridge | 567 metres (1,860 ft) | 2020[28] |
Arouca 516 | 516 metres (1,693 ft) | 2021[29] |
Ponte tibetano di Castelsaraceno | 586 metres (1,923 ft) | 2021[30] |
Sky Bridge 721 | 721 metres (2,365 ft) | 2022 |
Ponte tibetano di Sellano | 517.5 metres (1,698 ft)[31] | 2024[32] |
Gallery
-
under rope design bridges made on short distance
-
A simple suspension footbridge in Finland
-
A simple suspension bridge in Bohol, Philippines.
-
Capilano Suspension Bridge, supported by its handrail cables
-
Drac bridge at Lac de Monteynard-Avignonet
-
Closeup of the Drac bridge, showing stabilizing cables
-
Robert's Point Track, Franz Josef, New Zealand
See also
- Category:Simple suspension bridges
- Inca Bridge
- Stressed ribbon bridge (compression forces on the deck stabilize against swaying)
- Zip-line
- Suspension bridge types
References
- ^ Chisholm, Hugh, ed. (1911). . Encyclopædia Britannica. Vol. 04 (11th ed.). Cambridge University Press. pp. 533–538, see page 536.
8. (c) Suspension Bridges.—A suspension bridge consists of....."
- ^ Arthur Morley (1912). Theory of structures. Longmans, Green, and Co. pp. 482-484, 574.
simple suspension bridge.
- ISBN 978-0-521-04584-1. Appendix 2, footnote 373 on pages 285-287, footnote 1 on pages 520-521, footnote 5 on pages 521-522
- ^ Lockwood, E.H. (1961). "Chapter 13: The Tractrix and Catenary". A Book of Curves. Cambridge.
- Salmon, George (1879). Higher Plane Curves. Hodges, Foster and Figgis. pp. 287–289.
- ISBN 9783764314415
- PMID 25750153
- ^ ISBN 3-7643-1929-1.
- ^ ISBN 0-521-07060-0, 187–189.
- ISBN 0-262-11217-5.
- ^ "The Living-Root Bridge: The Symbol Of Benevolence". Riluk. 2016-10-10. Retrieved 2017-09-07.
- ^ "Living Root Bridge in Laitkynsew India". www.india9.com. Retrieved 2010-02-22.
- ^ "Ten Exceptional Living Root Bridges". The Living Root Bridge Project. 2017-05-10. Retrieved 2017-09-07.
- ^ "Cherrapunjee". www.cherrapunjee.com. Retrieved 2010-02-22.
- ^ "Living Bridges in India Have Grown for 500 Years (Pics)". TreeHugger, New York. Retrieved 2010-10-24.
- ^ The living root bridges of Cherrapunji, India
- ^ Otto, M. Rebekah; et al., "The Vine Bridges of Iya Valley", Atlas Obscura
- ^ Ruchira Paul (April 22, 2010). "Living architecture: The root bridges of India and Japan". Accidentalblogger.typepad.com. Retrieved April 3, 2015.
- ^ a b Henry Taylor Bovey (1882). Applied Mechanics. Vol. 2. Montreal: Printed by John Lovell & Son for the Office of the Minister of Agriculture, Canada. p. 150. pages 85-90
- ^ Fleeming Jenkin (1876). Bridges: an elementary treatise on their construction and history. Edinburgh: Adam and Charles Black. pp. 345.
simple suspension bridge.
pages 304-305 - ISBN 978-0-415-44172-8. page 145
- ^ ISBN 978-0-415-44172-8. page 108, 133-135
- ISBN 978-1-74104-236-8. page 253
- ^ "Des passerelles himalayennes" (in French). www.enviscope.com. Archived from the original on December 23, 2008. Retrieved 2009-03-04.
- ^ Arroyo Cangrejillo Bridge
- ISBN 9783763380879. Retrieved 2018-05-31.)
{{cite book}}
: CS1 maint: multiple names: authors list (link - ^ www.valtellina.it, Valtellina -. "Highest Tibetan Bridge in Europe Opens - Valtellina". www.valtellina.it. Retrieved 2018-09-24.
- ^ "Longest Tibet-style footbridge". www.guinnessworldrecords.com. Retrieved 2019-08-26.
- ^ "Parbat getting 'tallest and longest' bridge at home". myRepublica. 6 January 2020. Retrieved 1 May 2021.
- ^ "World's longest pedestrian suspension bridge is opening in Portugal". CNN Travel. 9 October 2020. Retrieved 10 October 2020.
- ^ "A Castelsaraceno il ponte tibetano più lungo al mondo" (in Italian). la Repubblica. 27 July 2021. Retrieved 22 January 2022.
- ^ https://traveltomorrow.com/europes-highest-pedestrian-suspension-bridge-is-now-open-in-italy/
- ^ https://www.pontetibetanosellano.com/
- Troyano, Leonardo Fernández (2003). "8.3.2 Catenary Bridges". Bridge Engineering: A Global Perspective. Thomas Telford. p. 514. ISBN 0-7277-3215-3.