The Evergreen Point Floating Bridge , officially the Bridge Governor Albert D. Rosellini , and is usually called SR 520 Bridge or 520 Bridge
The total length of the bridge is about 4,750 meters (15,580 ft). The floating section of 2,310 meters (7,580 ft) is the longest floating bridge in the world until April 11, 2016, when its replacement exceeds 40 meters (130 feet).
The bridge was named Evergreen Point, the westernmost of three small Eastside peninsions crossed by SR 520. (The other two were Hunts Point and Yarrow Point.) In 1988, the name was changed to 15 state governors, Albert D. Rosellini, who had advocated the construction.
Although there were plans to replace the bridge several years after its completion, it was not long before the investigation revealed the old bridge was in poor condition and unable to withstand the enormous dangers that it originally designed. These findings may accelerate plans to eventually replace them. In response to these dangers and the need to expand the current infrastructure, the construction of replacements begins in 2012; the new bridge opened in April 2016. The original bridge was closed for traffic on April 22, 2016.
Video Evergreen Point Floating Bridge
Histori
The bridge opened to commuter traffic on August 28, 1963, after three years of development. Built as a four-lane expressway bridge to provide easy access from Seattle to Eastside communities such as Bellevue, Kirkland and Redmond. The total cost of the bridge, in 1961 dollars, was $ 21 million (at least $ 127 million in 2011 dollars). To make up for this cost, the commuters paid 35 cents of tolls in each direction until 1979. The toll booth was then converted into a bus stop.
The bridge affects many communities in the Eastside. The Redmond population saw a dramatic increase, jumping from less than 1,500 in 1960 to 11,000 in 1970. It is the second floating bridge to cross Lake Washington; the first is the Lake Washington Floating Bridge, built in 1940 as part of Route 10 of the USA, the next part of Interstate 90, which in its construction is the largest floating structure ever constructed.
Maps Evergreen Point Floating Bridge
Opening Drawspan
The bridge was built by lottery in the middle that could open the boat too high to go under the bridge. The bridge opened by raising two 100-foot steel grating about 7 feet and moving the pontoon below.
In 1989, an electrical fault caused the drawspan to open during peak hours, causing one death and five injuries. In 2000, a gravel barge struck the bridge, shutting it for eleven days and causing damage of $ 500,000.
Alternate bridge
Only five years after the bridge was opened, a study commissioned by the state legislature was completed to find out how to provide the great demand for cross-lake transport. The study evaluated crossings of bridges and tunnels on the north and south of the bridge. To help provide the political lubrication necessary for any plan to move forward, the Trans-Lake Study is commissioned by the State of Washington. The study gathers 47 representatives of public institutions, the environment, business, and advocacy interests.
In 1997, Myint Lwin, head of the WSDOT bridge engineer, said that even with the improvements, the bridge is expected to last only about twenty years (until 2017). The bridge had to be closed for traffic in high winds, and even after seismic retrofit in 1999, the bridge was at risk of collapse during an earthquake. Due to the weight of various reinforcements over the years, the bridge deck ended up sitting about 1 foot (30 cm) lower on water than initially.
Since the bridge was built in the early 1960s, prior to the adoption of modern earthquake standards, its hollow support structure is likely to fail during major earthquakes. In addition, the vibrations induced by storm surges and high winds can damage the drawspan, anchor, and pontoon cables, which subdue them on structural failure. Even for a storm below the maximum threshold for failure to occur, the Washington State Department of Transport (WSDOT) is still closing the floating bridge for traffic. The original bridge carries two lanes of traffic in each direction, but excludes emergency shoulders or pedestrian and bicycle crossings. This raises traffic problems due to interruptions caused by car damage, accidents or maintenance will result in traffic backups.
In 2011, WSDOT broke the replacement bridge. On 2 April 2016, WSDOT held an opening ceremony, allowing the public to explore the upper deck of the new bridge on the west side. The replacement bridge opened for traffic to the west on April 11, 2016, and opened for traffic to the east on April 25, 2016. The old bridge is permanently closed at 23:00 PDT on April 22, 2016, with demolition completed by the end of 2016.
Construction
The cost of all improvements for the SR-520 between I-5 and I-405, including the new bridge, is estimated at $ 4.65 billion.
The first of 21 extended pontoons is positioned on August 11, 2012. Each pontoon is 360 feet (110 meters) long and 75 feet (23 meters) wide. Ponton was built in Aberdeen by Kiewit Construction. The construction of the pontoon is disrupted by errors and poor construction. Reports include workers installing the wrong size rebar, putting it in the wrong location, and even losing it altogether. Workers also pour concrete in a climate that is too wet or too cold. Some of the new pontoons have problems with cracks, which have been blamed on Kiewit's poor work. The independent auditor stated that there had been a long-standing poor quality work pattern and that WSDOT failed to force Kiewit to take corrective action. An inspector for construction called it a disaster waiting to happen, adding, "I will not drive over the bridge when the bridge was built."
At the end of February 2015, quite a number of new bridges were installed to block the tall ships that usually pass the raffle at the Rosellini Bridge. In early July 2015, the westernmost floating pontoon was moved to make room for the mounting of the western end of the bridge; on July 8, 2015, all the longitudinal pontoon for the new bridge was installed.
Tolling
When the bridge opened in 1963, a 35 cents toll was collected to finance the bridge. The withdrawal came to an end in 1979 when a citizen realized that the state was still burdening the drivers long after the bridge had been settled, thus revealing a breach of public trust by those who were watching the toll road.
The new fighting started in 2011 to finance the replacement of the original bridge.
To finance the new bridge, in May 2009, Governor Christine Gregoire signed ESHB 2211, authorizing the SR 520 bridge that began in 2010. Tolling actually began on December 29, 2011 and has assisted WSDOT in funding the project. The State Transportation Commission has proposed a cost of US $ 3.59 each way during peak periods. The rates proposed during other hours range from $ 0 to $ 2.87.
All tolling is done automatically without tollbooths. Freeing people without "Good to Go" pass is done by license plate. The Pulse Readers are located in the gantries in the eastern highlands, but an additional gantry on the eastern plains is added to facilitate the newly-strung bridge once opened.
The Eyman team promotes the Initiative 1125, which, among other measures, will prohibit the proposed timing of the bridge, the necessary funds to be used on roads collecting tolls, and the costs required to be determined by elected officials. The initiative was defeated by Washington voters.
References
External links
- Evergreen Point Floating Bridge in Structurae
- Bridge cameras (including some weather data)
- Photo gallery of the Department of Transport
- Opening daytime drawspan video, with comments from a WSDOT engineer on YouTube
Source of the article : Wikipedia
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