State Route 520 Floating Bridge - Revision history

Editor at 18:40, 26 April 2021

2021-04-26T18:40:18Z

← Older revision		Revision as of 18:40, 26 April 2021
Line 26:		Line 26:
	* Nine Elms to Pimlico bridge.		* Nine Elms to Pimlico bridge.
	* Pile foundations.		* Pile foundations.
		+	* Pontoon bridge.
	* Queensferry Crossing.		* Queensferry Crossing.
	* River engineering.		* River engineering.
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	* Water engineering.		* Water engineering.

−	=== External references ===	+	= External references =

	* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]		* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]

	[[Category:DCN_Commentary]] [[Category:DCN_Project_Knowledge]] [[Category:International]] [[Category:Projects_and_case_studies]] [[Category:Construction_techniques]]		[[Category:DCN_Commentary]] [[Category:DCN_Project_Knowledge]] [[Category:International]] [[Category:Projects_and_case_studies]] [[Category:Construction_techniques]]

Designing Buildings at 07:54, 25 December 2020

2020-12-25T07:54:38Z

← Older revision		Revision as of 07:54, 25 December 2020
Line 37:		Line 37:
	* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]		* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]

−	[[Category:~~International~~]] [[Category:~~Projects_and_case_studies~~]] [[Category:~~DCN_Project_Knowledge~~]] [[Category:Construction_techniques]]	+	[[Category:DCN_Commentary]] [[Category:DCN_Project_Knowledge]] [[Category:International]] [[Category:Projects_and_case_studies]] [[Category:Construction_techniques]]

Editor at 18:03, 26 June 2020

2020-06-26T18:03:03Z

← Older revision		Revision as of 18:03, 26 June 2020
Line 11:		Line 11:
	The use of floating bridges is typically limited by the wind and wave forces that are likely to be experienced. The ‘fetch’ is the unobstructed clear distance over the water that wind can travel to the bridge. The longer the fetch, the higher the wind and wave forces will be. Pontoons bend, heave and twist as a result of wind and wave forces, creating large stresses in the pontoons and anchor system. However, even in the event of a ‘100-year storm’ (a storm that statistically has 1% chance of occurring in any given year), the pontoons are designed so that they will not crack, and so the bridge will not sink.		The use of floating bridges is typically limited by the wind and wave forces that are likely to be experienced. The ‘fetch’ is the unobstructed clear distance over the water that wind can travel to the bridge. The longer the fetch, the higher the wind and wave forces will be. Pontoons bend, heave and twist as a result of wind and wave forces, creating large stresses in the pontoons and anchor system. However, even in the event of a ‘100-year storm’ (a storm that statistically has 1% chance of occurring in any given year), the pontoons are designed so that they will not crack, and so the bridge will not sink.

−	~~= Find out more =~~	+	= Related articles on Designing Buildings Wiki =
−		+
−	=== Related articles on Designing Buildings Wiki ===	+

	* 7 Engineering Wonders of the World.		* 7 Engineering Wonders of the World.
Line 20:		Line 18:
	* Bridges of the world.		* Bridges of the world.
	* Caisson.		* Caisson.
		+	* Chesapeake Bay Bridge-Tunnel.
	* Civil engineer.		* Civil engineer.
	* Cofferdam.		* Cofferdam.
Line 38:		Line 37:
	* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]		* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]

−	[[Category:International]] [[Category:Projects_and_case_studies]] [[Category:Construction_techniques]]	+	[[Category:International]] [[Category:Projects_and_case_studies]] [[Category:DCN_Project_Knowledge]] [[Category:Construction_techniques]]

Editor at 10:35, 3 January 2017

2017-01-03T10:35:06Z

← Older revision		Revision as of 10:35, 3 January 2017
Line 23:		Line 23:
	* Cofferdam.		* Cofferdam.
	* Driven piles.		* Driven piles.
		+	* Illusionist bridge.
	* Lucky Knot Bridge.		* Lucky Knot Bridge.
	* Nine Elms to Pimlico bridge.		* Nine Elms to Pimlico bridge.

Editor at 09:35, 15 November 2016

2016-11-15T09:35:16Z

← Older revision		Revision as of 09:35, 15 November 2016
Line 23:		Line 23:
	* Cofferdam.		* Cofferdam.
	* Driven piles.		* Driven piles.
		+	* Lucky Knot Bridge.
	* Nine Elms to Pimlico bridge.		* Nine Elms to Pimlico bridge.
	* Pile foundations.		* Pile foundations.

Editor at 10:35, 14 November 2016

2016-11-14T10:35:08Z

← Older revision		Revision as of 10:35, 14 November 2016
Line 25:		Line 25:
	* Nine Elms to Pimlico bridge.		* Nine Elms to Pimlico bridge.
	* Pile foundations.		* Pile foundations.
		+	* Queensferry Crossing.
	* River engineering.		* River engineering.
	* Thames barrier.		* Thames barrier.

Designing Buildings at 11:27, 1 September 2016

2016-09-01T11:27:28Z

← Older revision		Revision as of 11:27, 1 September 2016
Line 16:		Line 16:

	* 7 Engineering Wonders of the World.		* 7 Engineering Wonders of the World.
		+	* Akashi Kaikyo Bridge.
	* Bridge construction.		* Bridge construction.
	* Bridges of the world.		* Bridges of the world.

Designing Buildings at 12:58, 5 April 2016

2016-04-05T12:58:23Z

← Older revision		Revision as of 12:58, 5 April 2016
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	[[File:Aerial_520_Bridge.JPG\|link=File:Aerial_520_Bridge.JPG]]		[[File:Aerial_520_Bridge.JPG\|link=File:Aerial_520_Bridge.JPG]]

−	Washington State in northwest America ~~has~~ officially opened the world’s longest floating bridge. The ‘State Route 520 Bridge’, as it is known, is a six-lane pontoon structure 2.4 km in length. It ~~replaced a four-lane bridge that~~ was ~~completed in the early-1960s. It has been~~ constructed as part of the ‘Connecting Washington’ package of measures, ~~due to be~~ Washington State’s largest and greenest transportation investment ~~ever~~.	+	In March 2016, Washington State in northwest America officially opened the world’s longest floating bridge. The ‘State Route 520 Bridge’ (SR520), as it is known, is a six-lane pontoon structure 2.4 km in length. It was constructed as part of the ‘Connecting Washington’ package of measures, Washington State’s largest and greenest transportation investment.

−	The bridge boasts bigger and stronger pontoons and anchors than the previous bridge, along with a stormwater collection and treatment system to help improve the water quality of Lake Washington. A bus and carpool lane flows in either direction, as well as a 14 ft-wide bicycle and pedestrian path.	+	It replaced a four-lane bridge that was completed in the early-1960s. The bridge boasts bigger and stronger pontoons and anchors than the previous bridge, along with a stormwater collection and treatment system to help improve the water quality of Lake Washington. A bus and carpool lane flows in either direction, as well as a 14 ft-wide bicycle and pedestrian path.

−	Floating bridges ~~work by using~~ large water-tight concrete pontoons rigidly connected end-to-end, upon which the road deck is constructed. ~~It is able~~ to ~~float because~~ the ~~weight of the water displaced by the pontoons is equal~~ to the ~~weight~~ of the ~~concrete~~ structure, ~~as well as all traffic~~.	+	Floating bridges are constructed on large water-tight concrete pontoons rigidly connected end-to-end, upon which the road deck is constructed. Individual bridge pontoons are built on the land before being floated and towed to the bridge site. Once there, they are connected at each end to grounded approach structures, starting at the edge of the floating structure and then pieced together towards the bridge’s centre. Enormous cables hundreds of feet long hold the pontoons in place, connected to anchors buried deep in the lake bed.

−	~~Individual~~ bridge ~~pontoons are built on dry land before being floated and towed to~~ the ~~bridge site. Once there, they are connected at each end to grounded approach structures, starting at~~ the ~~edge~~ of the ~~floating structure and then pieced together towards the eventual~~ bridge’s ~~centre. Enormous cables generally hundreds of feet long hold~~ the ~~pontoons are held in place, connected to anchors buried deep in~~ the ~~lakebed~~.	+	A more conventional suspension bridge was not suitable for the location as the deepest point of Lake Washington is 214 ft, meaning that the bridge’s support towers would have to be approximately 630 ft tall, nearly the same height as the Space Needle.

−	There may be significant reasons why conventional suspension bridges are not suitable to the location. In the case of SR 520, a suspension bridge was not possible because they need to travel in a relatively straight line, and also because the deepest point of Lake Washington is 214 ft, meaning that the bridge’s support towers would have to be approximately 630 ft tall, nearly the same height as the Space Needle.	+	The use of floating bridges is typically limited by the wind and wave forces that are likely to be experienced. The ‘fetch’ is the unobstructed clear distance over the water that wind can travel to the bridge. The longer the fetch, the higher the wind and wave forces will be. Pontoons bend, heave and twist as a result of wind and wave forces, creating large stresses in the pontoons and anchor system. However, even in the event of a ‘100-year storm’ (a storm that statistically has 1% chance of occurring in any given year), the pontoons are designed so that they will not crack, and so the bridge will not sink.
−		+
−	The ~~design~~ of floating bridges is typically ~~controlled~~ by the wind and wave forces that are likely to be experienced. The ‘fetch’ is the unobstructed clear distance over the water that wind can travel to the bridge. The longer the fetch, the higher the wind and wave forces will be. Pontoons bend, heave and twist as a result of wind and wave forces, creating large stresses in the pontoons and anchor system. In the event of a ‘100-year storm’ (a storm that statistically has 1% chance of occurring in any given year), the pontoons are designed ~~to prevent large cracks from developing~~ that ~~would allow water to leak in~~ and ~~sink~~ the bridge.	+

	= Find out more =		= Find out more =

Editor at 09:19, 5 April 2016

2016-04-05T09:19:29Z

← Older revision		Revision as of 09:19, 5 April 2016
Line 1:		Line 1:
−	[[File:~~Aerial 520 Bridge~~.JPG]]	+	[[File:Aerial_520_Bridge.JPG\|link=File:Aerial_520_Bridge.JPG]]

	Washington State in northwest America has officially opened the world’s longest floating bridge. The ‘State Route 520 Bridge’, as it is known, is a six-lane pontoon structure 2.4 km in length. It replaced a four-lane bridge that was completed in the early-1960s. It has been constructed as part of the ‘Connecting Washington’ package of measures, due to be Washington State’s largest and greenest transportation investment ever.		Washington State in northwest America has officially opened the world’s longest floating bridge. The ‘State Route 520 Bridge’, as it is known, is a six-lane pontoon structure 2.4 km in length. It replaced a four-lane bridge that was completed in the early-1960s. It has been constructed as part of the ‘Connecting Washington’ package of measures, due to be Washington State’s largest and greenest transportation investment ever.
Line 32:		Line 32:
	* Water engineering.		* Water engineering.

−	External references	+	=== External references ===

	* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]		* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]

	[[Category:International]] [[Category:Projects_and_case_studies]] [[Category:Construction_techniques]]		[[Category:International]] [[Category:Projects_and_case_studies]] [[Category:Construction_techniques]]

Editor: Created page with "File:Aerial 520 Bridge.JPG Washington State in northwest America has officially opened the world’s longest floating bridge. The ‘State Route 520 Bridge’, as it is know..."

2016-04-05T09:19:02Z

Created page with "File:Aerial 520 Bridge.JPG Washington State in northwest America has officially opened the world’s longest floating bridge. The ‘State Route 520 Bridge’, as it is know..."

New page

[[File:Aerial 520 Bridge.JPG]]

Washington State in northwest America has officially opened the world’s longest floating bridge. The ‘State Route 520 Bridge’, as it is known, is a six-lane pontoon structure 2.4 km in length. It replaced a four-lane bridge that was completed in the early-1960s. It has been constructed as part of the ‘Connecting Washington’ package of measures, due to be Washington State’s largest and greenest transportation investment ever.

The bridge boasts bigger and stronger pontoons and anchors than the previous bridge, along with a stormwater collection and treatment system to help improve the water quality of Lake Washington. A bus and carpool lane flows in either direction, as well as a 14 ft-wide bicycle and pedestrian path.

Floating bridges work by using large water-tight concrete pontoons rigidly connected end-to-end, upon which the road deck is constructed. It is able to float because the weight of the water displaced by the pontoons is equal to the weight of the concrete structure, as well as all traffic.

Individual bridge pontoons are built on dry land before being floated and towed to the bridge site. Once there, they are connected at each end to grounded approach structures, starting at the edge of the floating structure and then pieced together towards the eventual bridge’s centre. Enormous cables generally hundreds of feet long hold the pontoons are held in place, connected to anchors buried deep in the lakebed.

There may be significant reasons why conventional suspension bridges are not suitable to the location. In the case of SR 520, a suspension bridge was not possible because they need to travel in a relatively straight line, and also because the deepest point of Lake Washington is 214 ft, meaning that the bridge’s support towers would have to be approximately 630 ft tall, nearly the same height as the Space Needle.

The design of floating bridges is typically controlled by the wind and wave forces that are likely to be experienced. The ‘fetch’ is the unobstructed clear distance over the water that wind can travel to the bridge. The longer the fetch, the higher the wind and wave forces will be. Pontoons bend, heave and twist as a result of wind and wave forces, creating large stresses in the pontoons and anchor system. In the event of a ‘100-year storm’ (a storm that statistically has 1% chance of occurring in any given year), the pontoons are designed to prevent large cracks from developing that would allow water to leak in and sink the bridge.

= Find out more =

=== Related articles on Designing Buildings Wiki ===

* 7 Engineering Wonders of the World.
* Bridge construction.
* Bridges of the world.
* Caisson.
* Civil engineer.
* Cofferdam.
* Driven piles.
* Nine Elms to Pimlico bridge.
* Pile foundations.
* River engineering.
* Thames barrier.
* The Iron Bridge.
* The Millau Viaduct.
* Water engineering.

External references

* Washington State - [http://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm Bridge facts]

[[Category:International]] [[Category:Projects_and_case_studies]] [[Category:Construction_techniques]]