The Worlds 10 Longest Bridge

Do you know the top 10 Longest Bridge in the World?

Well lets find out….

1. Lake Pontchartrain Causeway

The Lake Pontchartrain Causeway, or the Causeway, consists of two parallel bridges that are the longest bridges in the world by total length.[2] These parallel bridges cross Lake Pontchartrain in southern Louisiana. The longer of the two bridges is 23.87 miles (38.42 km) long. The bridges are supported by over 9,000 concrete pilings. The two bridges feature bascule spans over the navigation channel 8 miles (13 km) south of the north shore. The southern terminus of the Causeway is in Metairie , Louisiana , a suburb of New Orleans . The northern terminus is at Mandeville , Louisiana .

2. Donghai Bridge

Donghai Bridge (literally “ East Sea Grand Bridge ”) is the longest cross-sea bridge in the world and the longest bridge in Asia . It was completed on December 10, 2005. It has a total length of 32.5 kilometres (20.2 miles) and connects Shanghai and the offshore Yangshan deep-water port in China . Most of the bridge is a low-level viaduct. There are also cable-stayed sections to allow for the passage of large ships, largest with span of 420 m.

3. King Fahd Causeway

The King Fahd Causeway is multiple dike - bridge combination connecting Khobar , Saudi Arabia , and the island nation of Bahrain .

A construction agreement signed on July 8, 1981 led to construction beginning the next year. The cornerstone was laid on November 11, 1982 by King Fahd of Saudi Arabia and Sheikh Isa bin Salman al-Khalifa of Bahrain ; construction continued until 1986, when the combination of several bridges and dams were completed. The causeway officially opened for use on November 25, 1986.

4. Chesapeake Bay Bridge

The Chesapeake Bay Bridge (commonly known as the Bay Bridge ) is a major dual-span bridge in the U.S. state of Maryland ; spanning the Chesapeake Bay, it connects the state’s Eastern and Western Shore regions. At 4.3 miles (7 km) in length, the original span was the world’s longest continuous over-water steel structure when it opened in 1952. The bridge is officially named the William Preston Lane , Jr. Memorial Bridge after William Preston Lane, Jr. who, as governor of Maryland , implemented its construction.

5. Vasco da Gama Bridge

The Vasco da Gama Bridge (Portuguese: Ponte Vasco da Gama, pron. IPA: [’põt(?) ‘va?ku d? ‘g?m?]) is a cable-stayed bridge flanked by viaducts and roads that spans the Tagus River near Lisbon , capital of Portugal . It is the longest bridge in Europe (including viaducts), with a total length of 17.2 km (10.7 mi), including 0.829 km (0.5 mi) for the main bridge, 11.5 km (7.1 mi) in viaducts, and 4.8 km (3.0 mi) in dedicated access roads. Its purpose is to alleviate the congestion on Lisbon ’s other bridge (25 de Abril Bridge ), and to join previously unconnected motorways radiating from Lisbon .

6. Penang Bridge

The Penang Bridge (Jambatan Pulau Pinang in Malay) E 36 is a dual-carriageway toll bridge that connects Gelugor on the island of Penang and Seberang Prai on the mainland of Malaysia on the Malay Peninsula . The bridge is also linked to the North-South Expressway in Prai and Jelutong Expressway in Penang . It was officially opened to traffic on September 14, 1985. The total length of the bridge is 13.5 km (8.4 miles), making it among the longest bridges in the world, the longest bridge in the country as well as a national landmark. PLUS Expressway Berhad is the concession holder which manages it.

7. Rio-Niteroi Bridge

The Rio-Niteroi Bridge is a reinforced concrete structure that connects the cities of Rio de Janeiro and Niteroi in Brazil .
Construction began symbolically on August 23, 1968, in the presence of Queen Elizabeth II of the United Kingdom and Prince Philip, Duke of Edinburgh, in their first and thus far only visit to Brazil. Actual work begun in January, 1969, and it opened on March 4, 1974.
Its official name is “President Costa e Silva Bridge ”, in honor of the Brazilian president who ordered its construction. “Rio-Niteroi” started as a descriptive nickname that soon became better known than the official name. Today, hardly anyone refers to it by its official name.

8. Confederation Bridge

The Confederation Bridge (French: Pont de la Confédération) is a bridge spanning the Abegweit Passage of Northumberland Strait, linking Prince Edward Island with mainland New Brunswick, Canada. It was commonly referred to as the “Fixed Link” by residents of Prince Edward Island prior to its official naming. Construction took place from the fall of 1993 to the spring of 1997, costing $1.3 billion. The 12.9-kilometre (8 mi) long bridge opened on 31 May 1997.

9. San Mateo-Hayward Bridge

The San Mateo-Hayward Bridge (commonly called San Mateo Bridge ) is a bridge crossing California ’s San Francisco Bay in the United States , linking the San Francisco Peninsula with the East Bay . More specifically, the bridge’s western end is in Foster City , the most recent urban addition to the eastern edge of San Mateo . The eastern end of the bridge is in Hayward . The bridge is owned by the state of California , and is maintained by Caltrans, the state highway agency..

10. Seven Mile Bridge

The Seven Mile Bridge , in the Florida Keys, runs over a channel between the Gulf of Mexico and the Florida Strait, connecting Key Vaca (the location of the city of Marathon , Florida ) in the Middle Keys to Little Duck Key in the Lower Keys. Among the longest bridges in existence when it was built, it is one of the many bridges on US 1 in the Keys, where the road is called the Overseas Highway .

Dubai Metro Extension

Dubai Metro's Green Line extension study is in the design stage and will be completed in 60 months, according to a senior official at RTA.
"The Green Line extension study is in the design stage and was awarded in March to consultant Systra-Parson International," said Abdul Redha Abu Al Hassan, Director of Planning and Development, Rail Agency, RTA, in an exclusive to Emirates Business. "The project timeline is 60 months and it includes design, feasibility studies and preparation of tender documents."
He was speaking on the sidelines of the Mena rail 2009 organised by Terrapin.
The Green Line extension goes from Jed Hafs Station 2 through the Lagoons project and will then connect to the Emirates Road. "If we have the Blue Line in future, then it will also connect to that line," said Al Hassan.
The RTA's yearly budget is Dh12 billion to Dh15bn, he said. "It will be reduced over the years as most of the infrastructure work will be completed," he said.
RTA has plans to have up to 320km of rail by 2020.
Meanwhile, the RTA also started a new study called Integrated Rail Master Plan in February, Al Hassan said.
"It is a revision of the rail line footprint. It will look at the rail lines in Dubai and based on the current information and the growth of the emirate, we will revisit all the lines again and look at the conceptual layout and how to integrate all the lines," he said. "We will try to put new programmes for the new lines and the phases of the various projects."
The study has been assigned to Parsons Brinckerhoff and will be ready by 2010. "It is a revision of the line footprint. At the end of the study, RTA will revise its master plan," said Al Hassan.
Al Hassan said the Purple Line is on hold and RTA is waiting for developers to get back in order to make the project feasible.
"We were ready to go for tender but it has stopped due to the recession and the fact that many developers have stopped their projects. We do not want to do a project that is serving no one," he said. "It will take time to start again after we get new information from the developers who are rescheduling and replanning their projects."
Meanwhile, the Sufouh tram system has delayed its Phase 2 works due to major ongoing road works on one hand and the 'on hold' status of the Sama Dubai project (Jumeirah Hills) on the other.
"Phase 1 is not a problem but we are waiting for the project to materialise and then can go ahead with Phase 2," said Al Hassan. "The constructions of the stations in Phase 1 will commence by December and the project will be completed by April 2011."
The 9km Phase 1 will consist of 13 stations and will service Dubai Marina, both Media and Internet cities and the Al Sufouh area.
The first phase's lines are being built by the ABS consortium comprising Alstom, Besix and Serco.
The second phase is intended to service Burj Al Arab and Jumeirah Beach Hotel and will stretch 5km with six stations. The tram will link up with the Red Line of the Dubai Metro at three points on Sheikh Zayed Road, and with the monorail on The Palm Jumeirah where it meets Al Sufouh Road.
Al Hassan admitted that if certain projects are not ready, then some of the stations on the Red Line will not be operational.
"If developers will continue with their projects, then the stations will be operational," he said. "Otherwise the trains will go through the stations, which will be fully constructed."
The Red Line has finished 100 per cent of the construction of its viaduct (52km) and 10km of tunnel construction. Construction on all underground and above ground stations has almost been completed, he said.
The Green Line expects to finish 100 per cent of the viaduct this month and 100 per cent of tunnel construction. "All stations are expected to be finished by December and will be operational by March 2010," he said.

Earthquake could destroy 520 bridge, too, study says

An Article By LARRY LANGE

So you thought the Alaskan Way Viaduct was on shaky ground? Now you can worry about the state Route 520 bridge, too.

A recent engineering analysis, quietly discussed among state transportation officials and planners, says a magnitude-6.5 earthquake in the wrong spot could take out both structures.

The analysis says the viaduct fronting Elliott Bay and the bridge crossing Lake Washington have about the same ability to withstand the kind of major earthquake that occurs on average every 210 years. It is widely accepted that this region is at risk of catastrophic quakes.

To put it bluntly, a quake ranging in magnitude from 6.5 to 7.2, located close to the Earth's surface and near the spans, could destroy either structure or both.

The odds of this actually occurring have not been determined, state bridge engineer Patrick Clarke said.

Last year's major earthquake, centered near Olympia, registered a magnitude 6.8 but was centered 35 miles underground and 60 miles to the south -- too far away to destroy either span. Still, it was forceful enough to damage both, and to close the viaduct for several days for inspections and repairs.

Losing the bridge and viaduct, besides being deadly, could cripple traffic for years.

More than 225,000 drivers now use the two bridges every day, and would be forced to use side streets or other already-strained highways.

Rush-hour traffic backups could routinely extend south on Interstate 5 as far as the Boeing Access Road or east on Interstate 90 as far as Interstate 405, said Morgan Balogh, the state's regional traffic operations engineer.

"It gets ugly in a hurry, I'm sure," said Les Rubstello, manager of the state's Trans-Lake Washington study examining ways to improve mobility in the 520 corridor.

Replacing the 520 bridge could cost from $1.8 billion for four lanes to $7.4 billion for eight lanes, according to recent state estimates. Construction, depending on the option chosen, could last from nine to 11 years.

That the 520 bridge is as quake-vulnerable as the viaduct was startling news to some.

It was "new information for me," said King County Councilman Dwight Pelz, chairman of the council's Transportation Committee and a key player in planning a regional ballot measure to pay for major highway and transit improvements.

The quake analysis actually has been around for several months and was known to state officials and to some members of an advisory committee discussing whether to rebuild or replace 520's Evergreen Point Bridge.

Rubstello said the state didn't formally release details to avoid sounding "like we were crying wolf twice" after much-publicized reports about the viaduct's vulnerability to tremors.

In February, state Transportation Secretary Doug MacDonald urged legislators and Gov. Gary Locke to set aside money to plan replacements for both the viaduct and 520 bridge.

The letter did not mention the earthquake risk but said the 520 bridge is vulnerable to high winds and waves, which could break it apart.

"I've been flapping my lips at every meeting that it's an unsafe facility," said Redmond Mayor Rosemarie Ives. "Nobody wants to listen."

The quake analysis "serves to move 520 (replacement) up on the regional priority list," Pelz said.

Doing this, however, could reignite controversies about the effects of a bigger new bridge on the shorelines it connects. And some, including transit advocate Peter Hurley, want to see more detailed information before they agree that replacing the bridge makes more financial sense than retrofitting it to better resist earthquakes.

Engineers have long said that a major quake could fatally damage the viaduct, a 2.2-mile, double-deck structure that carries state Route 99 along the Seattle waterfront from the port docks to Aurora Avenue.

They have said the viaduct, which carries about 110,000 vehicles on an average weekday, could collapse if ground gives way under part of it, or if concrete cracks and support columns shear.

In a report issued a year ago, a team of engineers recommended replacing the viaduct, saying retrofitting it to meet modern earthquake standards didn't make sense.

That report came four months after an earthquake did more than $1.7 million in damage to the viaduct, cracking it and prompting crews to close parts of it for several days while it was shored up.

The same Feb. 28, 2001, earthquake that opened cracks in the viaduct did minor damage to the 520 bridge, loosening bolts in a joint on the western approach span.

A 1993 earthquake-evaluation study concluded that the tops of the 520 bridge's approach supports near each shoreline, filled with concrete five feet down from the top, would bend enough in an earthquake to hold up.

But that's no longer accepted. Below those solid "caps," the supports are hollow shells with 5-inch outer walls. State officials said researchers in California later became skeptical about how well hollow columns would hold up.

After a tug and barge hit and shattered one of the 520 bridge columns two years ago, Washington state engineers re-evaluated the earlier conclusion.

And in a memo three months ago, two state engineers said the caps wouldn't bend enough in an earthquake to keep the bridge supported.

That conclusion also was included in a brief internal state Transportation Department report in January. This said that even though the double-deck viaduct and the floating 520 bridge are built differently, the earthquake risks to the two structures when faced with the 210-year earthquake "are almost identical."

Rubstello said state analysts are just beginning to calculate how motorists would react to the simultaneous loss of both structures. Balogh, the state engineer, said backups would be longer on I-5 and I-90 and congestion would worsen on other highways as drivers tried to compensate for the loss of the two spans.

"You're not going to sit on the freeway for an hour. You're going to risk it on an arterial" (street), he said.

Some think the earthquake risk makes the 520 bridge a higher replacement priority. State officials have said retrofitting the 520 bridge for safety is not worthwhile because of its age, though they did do $1.14 million in retrofitting work in 1999.

Even people in Seattle's Montlake neighborhood, where the bridge's west approach is located, agree it should be replaced, said Jonathan Dubman, president of Montlake Community Club.

But the question is: With what? The advisory committee hasn't decided how many lanes a new span should have. That's a big issue in Dubman's neighborhood where, depending on the width of a new bridge, people living 200 feet from it now "could be as close as 20 feet to the new highway."

"The neighborhood would support an effective transportation solution that would improve the quality of life along the (520) corridor and through the region," Dubman said. "But we have some work to do to figure out a solution."

Dubai's Mile-Long Super Arch Bridge

Dubai is going ahead with another ambitious project which is a super arch bridge. Dubai's next super structure will stand higher than the George Washington Bridge (604 ft.) but fall short of San Francisco's existing Golden Gate Bridge (746 ft.).

I-35W Bridge Collapse

A lesson which had made our bridge engineering safer.

I-35W Bridge History

• Built in 1964 by Hurcon Inc. and Industrial Construction Company.
• Steel trusses and deck were constructed by Industrial Construction Company in the summer of 1965.
• Bridge opened to traffic in 1967.
• Scheduled for reconstruction in 2020-25.

Stats

• Bridge carries 144,000 vehicles per day; including 4,760 commercial vehicles.
• Similar bridges in Minnesota include the Hwy. 123 bridge in Sandstone and the Hwy. 23 bridge over the Mississippi River in St. Cloud.

Design

• Deck steel truss is made up of three parts: deck, superstructure and substructure (the structure under water).
• Bridge has a split deck (longitudinally parallel to traffic) and is 113 feet, 4 inches wide.
• Size/length: 1,907 feet long, eight lanes.

Inspection History

• Had been inspected annually since 1993; before that, was inspected every two years
• Last fully inspected in 2006. Partial inspections were conducted in 2007; to be complete in fall 2007 (see inspection reports on I-35W bridge online at www.mndot.gov -- scroll to bottom of page to find documents)
• The 2006 Fracture Critical Bridge Inspection Report, prepared by a MnDOT bridge inspection team, describes specific problems that caused the superstructure (part of bridge above water) to receive a poor rating. The poor rating can be attributed to corrosion at some areas where the paint system has deteriorated, poor weld details in the steel truss members and floor beams, bearings that are not moving as they were designed to move, and existing fatigue crack repairs to the truss cross beam and approach spans.
• Deficiencies were acknowledged in the 2005, 2006 and 2007 inspection reports.

• MnDOT had taken several steps to address these deficiencies. Some cracking in the approach spans was repaired or was being monitored. The Bridge Office had contracted with the University of Minnesota in 1990 to evaluate the fatigue stresses within the truss. Field tests were conducted. Measured and calculated stress ranges were less than the fatigue threshold, therefore, it was concluded that fatigue cracking was not expected in the deck truss. The following actions were recommended:
• Structural components of the main truss with the highest stress ranges should be inspected thoroughly, every two years.
• Critical locations of the floor trusses had high stress ranges, and should be inspected every six months.

• Although the report concluded that fatigue cracking was not expected to be a problem for the weld details used on the truss, MnDOT contracted with URS (a private firm) in 2003 to do a more in-depth fatigue and fracture analysis, and to determine whether the fracture of any single truss member would result in collapse of the bridge or whether the traffic load would be safely carried by other members of the bridge. URS made three recommendations in January 2007:

1) Add redundant plating over the most critical 52 truss members,

2) Conduct a visual examination of all suspected weld details and remove measurable defects at suspected weld details of all 52 fracture critical truss members, or,

3) Do a combination of both 1) and 2).

MnDOT had begun inspection of the weld details and no weld cracks were detected. Therefore, MnDOT did not proceed with option 1 at that time. MnDOT intended to complete the inspection of the weld details on all of the remaining members after the completion of the current construction project.

Structurally deficient bridges

• A bridge is rated as “structurally deficient” when part of the bridge is found to be in poor condition. Many bridges in poor condition are still safe for use. As deterioration continues, engineering analysis is sometimes necessary to re-compute the safe load capacity of the bridge. If the safe load capacity is less than today’s legal truck load (80,000 pounds), the bridge is posted at the newly computed safe load capacity.

• The I-35W bridge was rated safe for legal truck loads and permitted overweight truck loads of up to 136,000 lbs. The bridge was not under any restrictions.

· The condition of different parts of a bridge is rated on a scale of 1 to 9 (7, 8, or 9 are good condition ratings, 6 is satisfactory, 5 is fair, 4 is poor, 3 is serious, 2 is critical and 1 is closed). A structurally deficient bridge is one for which the deck, the superstructure or the substructures are rated in condition 4 or less. For this bridge, the superstructure was rated 4.

• In Minnesota, there are 1,097 bridges that are considered structurally deficient and that have a sufficiency rating less than or equal to 80. Of these bridges, 106 are on the state trunk highway system and 991 are on the local system.

Federal report on bridges (NBIS database)

• The National Bridge Inspection Standards require states to annually report condition ratings for all bridges in their states to the Federal Highway Administration (FHWA). Each MnDOT district has inspectors who are trained to inspect and rate bridge condition. That information is forwarded to MnDOT’s Bridge Office where it is compiled and forwarded to the FHWA. The FHWA uses that data to determine which bridges are structurally deficient and functionally obsolete.

Recent work on the bridge

• Work involved concrete and joint repair, lighting and guardrail installation
• Work was scheduled to be complete Sept. 30.
• Cost for the work is $9 million.

Tacoma Bridge Disaster

http://www.youtube.com/watch?v=HxTZ446tbzE

The Tacoma Bridge Engineering Disaster has been a turning point which had saved a lot of lives and making bridge engineering a lot safer.

The original Tacoma Narrows Bridge was opened to traffic on July 1, 1940. It was located in Washington State, near Puget Sound.

The Tacoma Narrows Bridge was the third-longest suspension bridge in the United States at the time, with a length of 5939 feet including approaches. Its two supporting towers were 425 feet high. The towers were 2800 feet apart.

Design

Prior to this time, most bridge designs were based on trusses, arches, and cantilevers to support heavy freight trains. Automobiles were obviously much lighter. Suspension bridges were both more elegant and economical than railway bridges. Thus the suspension design became favored for automobile traffic. Unfortunately, engineers did not fully understand the forces acting upon bridges. Neither did they understand the response of the suspension bridge design to these poorly understood forces.

Furthermore, the Tacoma Narrows Bridge was built with shallow plate girders instead of the deep stiffening trusses of railway bridges. Note that the wind can pass through trusses. Plate girders, on the other hand, present an obstacle to the wind.

As a result of its design, the Tacoma Narrows Bridge experienced rolling undulations which were driven by the wind. It thus acquired the nickname "Galloping Gertie."

Failure

Strong winds caused the bridge to collapse on November 7, 1940. Initially, 35 mile per hour winds excited the bridge's transverse vibration mode, with an amplitude of 1.5 feet. This motion lasted 3 hours.

The wind then increased to 42 miles per hour. In addition, a support cable at mid-span snapped, resulting in an unbalanced loading condition. The bridge response thus changed to a 0.2 Hz torsional vibration mode, with an amplitude up to 28 feet. The torsional mode is shown in Figures 1a and 1b.

Figure 1a. Torsional Mode of the Tacoma Narrows Bridge

Figure 1b. Torsional Mode of the Tacoma Narrows Bridge
The torsional mode shape was such that the bridge was effectively divided into two halves. The two halves vibrated out-of-phase with one another. In other words, one half rotated clockwise, while the other rotated counter-clockwise. The two half spans then alternate polarities.
One explanation of this is the "law of minimum energy." A suspension bridge may either twist as a whole or divide into half spans with opposite rotations. Nature prefers the two half-span option since this requires less wind energy.

The dividing line between the two half spans is called the "nodal line." Ideally, no rotation occurs along this line.

The bridge collapsed during the excitation of this torsional mode. Specifically, a 600 foot length of the center span broke loose from the suspenders and fell a distance of 190 feet into the cold waters below. The failure is shown in Figures 2a and 2b.

Figure 2a. Failure of the Tacoma Narrows Bridge

Figure 2b. Tacoma Narrows Bridge after the Failure

Failure Theories

Candidates

The fundamental weakness of the Tacoma Narrows Bridge was its extreme flexibility, both vertically and in torsion. This weakness was due to the shallowness of the stiffening girders and the narrowness of the roadway, relative to its span length.

Engineers still debate the exact cause of its collapse, however. Three theories are:

1. Random turbulence
2. Periodic vortex shedding
3. Aerodynamic instability (negative damping)

These theories are taken from Reference 1. Aerodynamic instability is the leading candidate.

Random Turbulence

An early theory was that the wind pressure simply excited the natural frequencies of the bridge. This condition is called "resonance." The problem with this theory is that resonance is a very precise phenomenon, requiring the driving force frequency to be at, or near, one of the system's natural frequencies in order to produce large oscillations. The turbulent wind pressure, however, would have varied randomly with time. Thus, turbulence would seem unlikely to have driven the observed steady oscillation of the bridge.

Vortex Shedding

Theodore von Karman, a famous aeronautical engineer, was convinced that vortex shedding drove the bridge oscillations. A diagram of vortex shedding around a spherical body is shown in Figure 3. Von Karman showed that blunt bodies such as bridge decks could also shed periodic vortices in their wakes.

A problem with this theory is that the natural vortex shedding frequency was calculated to be 1 Hz. This frequency is also called the "Strouhal frequency." The torsional mode frequency, however, was 0.2 Hz. This frequency was observed by Professor F. B. Farquharson, who witnessed the collapse of the bridge. The calculated vortex shedding frequency was five times higher than the torsional frequency. It was thus too high to have excited the torsional mode frequency.

In addition to "von Karman" vortex shedding, a flutter-like pattern of vortices may have formed at a frequency coincident with the torsional oscillation mode. Whether these flutter vortices were a cause or an effect of the twisting motion is unclear.

Figure 3. Vortex Shedding around a Spherical Body

Aerodynamic Instability

Aerodynamic instability is a self-excited vibration. In this case, the alternating force that sustains the motion is created or controlled by the motion itself. The alternating force disappears when the motion disappears. This phenomenon is also modeled as free vibration with negative damping.

Airfoil flutter and transmission line galloping are related examples of this instability. Further explanations of instability are given in References 2 , 3, and 4.

The following scenario shows how aerodynamic instability may have caused the Tacoma Narrows Bridge to fail. For simplicity, consider the motion of only one span half.

Assume that the wind direction was not perfectly horizontal, perhaps striking the bridge span from below, as shown in Figure 4a

Thus, the bridge is initially at an angle-of-attack with respect to the wind. Aerodynamic lift is generated because the pressure below the span is greater than the pressure above. This lift force effectively places a torque, or moment, on the bridge. The span then begins to twist clockwise as show in Figure 4b. Specifically, the windward edge rotates upward while the leeward edge rotates downward.

The span has rotational stiffness, however. Thus, elastic strain energy builds up as the span rotates. Eventually, the stiffness moment overcomes the moment from the lift force. The span then reverses its course, now rotating counter-clockwise

The span's angular momentum will not allow it to simply return to its initial rest position, however. The reason is that there is little or no energy dissipation mechanism. Thus, the span overshoots its initial rest position. In fact, it overshoots to the extent that the wind now strikes the span from above as shown in Figure 4c. The wind's lift force now effectively places a counter-clockwise moment on the span.

Once again, strain energy builds up in the span material. Eventually, the stiffness moment exceeds the moment from the wind's lift force. The span thus reverse course, now rotating clockwise. Again, it overshoots its rest position. The cycle of oscillation begins anew from the position shown in Figure 4a, except that the span now has rotational velocity as it passes through the original rest position.

The cycles of oscillation continue in a repetitive manner.

Note that the wind force varies as a function of the span angle during the cycle. The wind force may also vary with the angular velocity. The wind force is not a function of time, however.

Eventually, one of two failure modes occurs. One possibility is that the span experiences fatigue failure due to an excessive number of stress reversals. The other is that the angular displacement increased in an unstable manner until the material is stressed beyond its yield point, and then beyond its ultimate stress limit.

In reality, these two failure modes are interrelated. For example, accumulated fatigue effectively lowers the yield and ultimate stress limits. Regardless, the bridge collapses.

As a final note, the aerodynamic instability oscillation is not a resonant oscillation since the wind does not have a forcing frequency at, or near, the bridge's torsional mode frequency. Some physics and engineering textbooks mistakenly cite the Tacoma Narrows Bridge as an example of resonance. This problem is discussed in Reference 5.

Nevertheless, the bridge's collapse remains the most well-know structural failure due to vibration.

Replacement Bridge

A new Tacoma Narrows Bridge was built in 1950, as shown in Figure 5. The second bridge had truss-girders which allowed the winds to pass through. It also had increased torsional stiffness because it was thicker and wider. Furthermore, wind tunnel testing was performed to verify the design of the new bridge prior to its construction.

References

1. James Koughan, "The Collapse of the Tacoma Narrows Bridge, Evaluation of Competing Theories of its Demise, and the Effects of the Disaster of Succeeding Bridge Designs," The University of Texas at Austin, 1996.
2. Den Hartog, Mechanical Vibrations, Dover, New York, 1985.
3. H. Bachmann, et al., Vibration Problems in Structures, Birkhauser Verlag, Berlin, 1995.

4. M. Levy and M. Salvadori, Why Buildings Fall Down, Norton, New York, 1992.

5. K. Billah and R. Scanlan, "Resonance, Tacoma Narrows Bridge Failure, and Undergraduate Physics, Textbooks;" American Journal of Physics, 1991.

Figure 5. The Replacement Tacoma Narrows Bridge, Built in 1950

100 Years Bridge Oberndorf - Laufen

Bridge construction has gone back along way in history

Oberndorf has witnessed a large number of devastating floods during the last centuries. The first record of a bridge being washed away dates back to 1316. The damage was often caused by flotsam which was caught between the wooden bridge pylons and forced the water to dam up. Ultimately the bridges were often just washed away. During the last decade of the 19th century four floods cased great damage, and a decision was made to relocate the town to a more elevated plateau.

The Bavarian Laufen and Austrian Oberndorf developed the plan to construct a stable bridge made of stone and iron incorporating a greater span. As the bridge was in close proximity to both the old town square of Laufen and the new centre of Oberndort, an aesthetic design was implemented.
The two-pylon construction had three apertures, the largest of which was on the Austrian side to allow for shipping needs. The construction was made of 648 tonnes of Martin River iron ore, with a chain-like curved upper cable and a straight lower cable. The facing of the pillars and decorative elements required an additional 67 tonnes of material to ensure a pleasing design. Eagles with spread wings were placed upon the bridge portals, adding to the elegant impression of the construction. The bridge was inaugurated on the 2nd of June 1903 in a collective festival of inhabitants from Laufen and Oberndorf.

Sungai Johor Bridge

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The Sungai Johor Bridge will definitely be the longest cable stayed bridge in Malaysia

The cable-stayed bridge has a single central plane of cables in a harp configuration.

Construction of the cable-stayed bridge across the Johor River began in 2006; the bridge was first planned in 1996 but the Asian currency crisis put paid to it at the time. The bridge will connect Kong Kong on the western bank to Teluk Sengat in the east.

The preliminary and detailed design and engineering work was carried out by COWI Consulting Engineers and Planners AS and Ranhill Consulting Sdn Bhd for Senai Desaru Expressway Berhad (the concession holder). Three Ranhill engineers spent six months in Denmark with COWI designers to develop the design of the bridge.

The construction was undertaken by Ranhill Engineers and Constructors Sdn Bhd, foundations were constructed by Ranhill Antara Koh Sdn Bhd, the steel construction was the remit of Jawala and MBEC. Waiko Engineering Sdn Bhd are construction subcontractors, the stay cables and incremental launching of sections were contracted to VSL International.

"The new road will be a four-lane dual carriageway and will improve access across the region of Johfor."

BRIDGE STRUCTURE

The main span of the bridge is 500m and the pylon height is 150m above the surface of the river. The cable-stayed design of the bridge is in a harp configuration but in a single central plane (only one set of stay cables). This means that the cables are in a near-parallel arrangement, by virtue of the fact that the cables are attached to various points on each of the two ‘A’ shaped concrete pylon towers.

Each tower has a foundation of 34-bore 2m-diameter steel cased piles. The result of this is that the height of attachment of each cable on the tower is similar to the distance from the tower along the roadway to its lower attachment.

The middle 739m of the bridge has a composite deck with a 250mm-thick precast concrete deck slab and a closed structural steel skirt (3.5m deep). There are two 484.5m deck sections on either side of the central section and these consist of a concrete box girder structure.

Worlds Longest cable-stayed bridge span is completed

The worlds longest cable stayed bridge was officially opened on 30 June 2008.

The two cantilevers of China's Sutong Bridge have been connected, creating the world's longest cable-stayed bridge span. COWI has provided construction management on the project, among other services.

China's Sutong Bridge crosses the Yangtze River upstream from Shanghai. Its 40-metre wide bridge deck will carry a six-lane road plus emergency lanes. The main span of the bridge is 1088 metres, making it the longest cable-stayed bridge in the world.

COWI is providing services that include design assistance and design review, design of scour protection, aerodynamic investigations, construction control and construction management.

The Sutong Bridge, China, close to completion.
Image gallery

Ahead of schedule

COWI chief project manager Lars Thornfeldt Sørensen has been with the project since it began in 2003.
He says, "The project has run smoothly and the closure of the main span was completed nine months ahead of schedule. The significant volume of river traffic could have been a major problem but the Chinese authorities organised timed closures to allow for the hoisting of bridge girder segments."

The final bridge segment connecting the two spans was floated down river and hoisted into place at the beginning of June.

Long cantilevers

The connection of the bridge cantilevers is more than just a ceremonial occasion. Prior to connection, the two record long cantilevers were sensitive to strong winds and therefore it was important to join the cantilevers before the beginning of the typhoon season. Joining them creates a far stronger structure.

Millau Viaduct – World's Tallest Bridge

Extreme Engineering Marvel

Mankind has certainly moved on to the next challenge of constructing on what was thought to be as the impossible by our predecessors. Credits to the Engineers.

To me there are few things more impressive than being on a man-made structure, such as a very tall building or a bridge, and viewing blue sky above and clouds below. Of, course for this to occur the structure has be be rather high and the clouds low.

This is why I was immediately impressed when a friend sent me pictures of the Millau Viaduct, which crosses the valley of the Tarn River valley near the city of Millau in the mountains of southern France.

Normally it is the high mountains that present a challenge to engineers building roads that connect two or more points. However, in case of the Millau Viaduct, the mountain area through which the A75 autoroute, also known as la Méridienne, passes is apparently rather high most of the way until it reaches the Tarn River valley.

Bridge with blue sky above and clouds below.

Bridge spans valley of the Tarn River.

 

A Joint Franco-British Project

As can be seen from the picture at the right, one has to traverse a long, winding road down the mountain on one side of the valley and then immediately repeat the process while climbing up the mountain on the other side of the valley.

In addition to the kilometers / miles and time added by the trip down into the valley and back up into the mountains, time was also lost in the past to traffic congestion in the town and on the two lane bridge across the Tarn River. It is estimated that the bridge over the valley has shortened the driving distance between the Paris and the Mediterranean coast of France by 100 kilometers (about 62 miles) and, during the summer tourist season, reduced travel time by as much as four hours.

Construction of the bridge was a joint Franco-British project with help from companies in other European countries. Financing for the 394 million Euro (U.S. $524) project was provided by the French construction firm Eiffage. As a result of corporate mergers*, the Eiffage frim includes the firm that built the Eiffel Tower in Paris which, at the time of its completion in 1887, was the tallest structure in the world. This is obviously a company with long experience in being involved with construction of structures of record setting size. British architect Norman Foster designed the bridge, which has come to be viewed both as a work of art as well as a construction marvel, while the French bridge engineer, Dr. Michel Virlogeux, provided the engineering design.

While planning began in the late twentieth century, actual construction did not begin until December 2001 and its 2005 target completion date was achieved a little early when it was formally dedicated on December 14, 2004 and opened to traffic on December 16, 2004.

The Millau Viaduct is an artistic and engineering marvel. It currently holds the record for having the highest piles (the pilers rising from the ground and supporting the bridge from below) of any bridge in the world with its highest being 244.96 meters (803.7 feet) and the highest mast (the pilers rising up from the top of the bridge and holding the suspension cables) which towers 343 meters (1,125 feet) above the roadbed of the bridge. It also has a claim to having the highest roadbed of any bridge in the world with its roadbed reaching 270 meters (885.8 feet) above the river below.

However, the roadbed of the Royal Gorge Bridge in Colorado in the United States tops this with its roadbed which towers 1,053 feet (321 meters) above the river below. Based upon height of roadbed, the Royal Gorge Bridge is the highest in the world while based upon mast height, the Millau Viaduct is the highest in the world. Regardless of which is the highest, the Millau Viaduct is the clear winner in terms of length and beauty.

Famous Bridges

Look back into history of some of the famous bridges around the world

Look up to the tallest bridge in the United States at the Royal Gorge Bridge in Colorado. It is the tallest suspension bridge in the world, looming above the Arkansas River at 1,053 feet. You can even walk across the bridge’s wooden planks, if you can deal with the vertigo you may experience. Only taking six months to build, it cost $350,000 in 1929. This bridge was built with tourists in mind, not as a transportation mode. It is at the top of the list for visited attractions in Colorado.

See St. Petersburg Cathedral, The London Eye, Canary Wharf and so much more from the London Tower Bridge walkways in London, England. The two towers span over the Thames River with two glassed in walkways for pedestrians to walk. Previously, the London Bridge was the only way in and out of England’s capital city. As the only movable bridge on the Thames, it moved up and down over 1,000 times a year after it first opened in 1894. Today, very few ships travel down the Thames River and it only opens about 100 times annually.

Cross the Brooklyn Bridge by car and you will be among 144,000 other vehicles daily. This bridge boasts several “firsts” in the world of bridges. It was the first suspension bridge to use steel cable wires in its construction, and it was also the first to use caisson devices in explosions. When it was built in 1883, it was the longest suspension bridge at 3,460 feet. However, today the Japanese Akashi Kaikyo Bridge at 12,626 feet is the longest suspension bridge in the world.

Ride in a railway car over the Garabit Viaduct Bridge from the Garabit valley to the south of France. This famous red bridge was built from steel beams with triangle shaped holes in a truss pattern. This allowed the windy area’s bridge to remain stable rather than swaying when the wind hit it. This bridge was designed by none other than Gustave Eiffel, known as the famous architect of France’s Eiffel Tower.

There is enough cable wire from the Golden Gate Bridge in San Francisco to circle around the world several times. The men that worked on the bridge had a special name attached to them, the “Halfway to Hell Club.” That's how dangerous their jobs were. A safety net was strewn under the workers. It saved the lives of 19 of the bridge builders during it’s construction. A million vehicles, and counting, have gone over the Golden Gate since it was built in 1937.

Observe the remains of the Tacoma Narrows Bridge at the National Register of Historic Places. Its remains were dredged from Puget Sound for safe keeping. After its demise, bridges were never built in the same way again. When this bridge was completed in the 1940s, it got the name “Galloping Gertie” because of its rocking action. It actually made drivers and passengers car sick while driving over it. Thankfully, no lives were lost when it finally fell apart in 42 mph winds and crashed into the water below. The solid girders used in the construction of the Tacoma Narrows Bridge caused it to act in the unstable manner. A new type of construction eased the wind and kept bridges from excessive swaying.

Chappel Viaduct in England

It’s amazing how people can construct such a massive structure back during the old days.

Renowned as being the second largest brick built structure in England, the first being recognised as Battersea Power Station, the Chappel Viaduct is situated near Wakes Colne in Essex and spans the picturesque Colne Valley. It presently still supports the Sudbury to Marks Tey line which regularly connects with trains to and from London's Liverpool Street Station along the main line.

The foundation stone for this man made wonder was laid on the 14th September 1847. A bottle containing a newly minted sovereign, a half-sovereign, a shilling, a sixpence and a four-penny piece was placed underneath this stone. This bottle and all its contents were stolen shortly after the laying ceremony; the culprit was caught after he tried to pass over a brand new sovereign coin in the nearby Rose and Crown public house.

Chappel Viaduct is 1,066ft long and some 5 to 6 million bricks are believed to have been used in its construction. A work force of 606 men known at the time as 'navvies' were employed to complete the work which took two years, this was relatively fast for such a large structure. The Viaduct has 32 arches; each having a span of 30ft and at its maximum the height is 75ft. Although so many bricks were used in the construction, to save money and to cut down on weight, the piers were left hollow.

The engineer of the viaduct was Peter Schuyler Bruff and his plan was for the line to continue on as far as Ipswich in Suffolk, but the railway company did not have sufficient funds for this. Bruff later built the line himself and is also credited for founding the Essex seaside resort of Clacton-on-Sea.

On the 2nd July 1849, the first passenger train crossed the viaduct from Colchester to Sudbury carrying an official party. A large crowd greeted the honoured guests at Sudbury despite its station still being unfinished.

To this day Chappel Viaduct is in daily use by trains and is well worth a visit if you are in the area. It attracts many tourists and visitors every year and is a highly photographed structure. Bordering the viaduct is The Chappel Millennium Green and as the name suggests this was opened to celebrate the Millennium. It contains a walk around area and children's play area which should keep the kids amused while you take in this wonder.

Construction of Agas-Agas Bridge in South Leyte – ahead of schedule with 87% completed

Latest development of progress of Agas-Agas bridge construction

Tacloban City (April 26) -- Department of Public Works and Highways Secretary Hermogenes Ebdane, Jr. was a picture of contentment when earlier this month of April, he inspected the near completion of the Agas Agas Bride or Viaduct project in Sogod, Southern Leyte.

Considered as one of the vital road network in Eastern Visayas, the Agas-Agas Bridge Project is already 87 percent complete, much more, 8.17 percent ahead of the schedule. the Agas-Agas Bride Project is expected to be completed on August of 2009.

The Project contractor has completed much of the programmed works because of the good weather condition in the area. If the good weather prevails contractor will complete the project ahead of schedule.

DPWH Secretary Ebdane who was accompanied by Undersecretary for Visayas Operations Rafael Yabut, discussed with the contractors and consultants the possibility of providing several improvements which will complement with the bridge.

The DPWH Secretary was referring to the putting up a bridge view deck and other additional works such as parking area, rest house, bridge bituminous concrete surface course, bridge electrical provision and other related works.

"Because it is considered as one of the considered engineering feats in the country, the Agas-Agas Bridge has the potential of becoming a tourist destination in Eastern Visayas," Secretary Ebdane said.

The P995 Milliion bridge project is jointly funded by the Japan Bank for International Cooperation and the Goivernment of the Philippines.

The bridge project includes the construction of 350 meters of cantilever pre-stressed bridge and 1.15 kilometers of portland concrete cement pavement, improvement of drainage system and construction of slope protection and other structures

Tunnel's cost may be deceiving

Tunnel's cost may fool us all

Check out this articel from Prof Danny Westneat

A professor at Oxford University in England has done a compelling series of studies trying to get at why big public-works projects such as bridges, tunnels and light-rail systems almost always turn out to be far more costly than estimated.

Danny Westneat

Seattle Times staff columnist

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"We don't envision any cost overruns on this project." — Pearse Edwards, spokesman for Gov. Chris Gregoire

"The way I see it, I don't think we're going to have overruns." — State House Transportation Chairwoman Judy Clibborn

"There won't be any cost overruns." — State Transportation Secretary Paula Hammond

These people are all talking about the tunnel to be drilled beneath downtown Seattle, as a replacement for the creaky Alaskan Way Viaduct. How would you characterize their statements? Informed? Promotional? Utopian? Foolish?

A new body of social-science research about the psychology of public-works projects suggests a more pointed set of words may apply. Deluded. Deceptive.

Or: Lying.

That last one is such a loaded charge that I want to be clear: The research is not specific to these public officials, or to our struggle to figure out what to do with the aging viaduct.

But a professor at Oxford University in England has done a compelling series of studies trying to get at why big public-works projects such as bridges, tunnels and light-rail systems almost always turn out to be far more costly than estimated.

"It cannot be explained by error," sums up one of his papers, matter-of-factly. "It is best explained by strategic misrepresentation — that is, lying."

The professor, Bent Flyvbjerg (pronounced flew-byair), has become a flash point in civic-planning circles. Some think he's a rock star; others say his analysis is too cynical.

It started seven years ago, when he published the first large study of cost overruns in 258 mega-transportation projects. He found that nine out of 10 came in over budget, and that the average cost overrun was nearly 30 percent. Rail systems had an average cost escalation of 45 percent.

Our own Sound Transit light-rail system was not included in the study, but it fits the profile. Its budget soared by more than 100 percent, forcing planners to halve the length of the rail line. The shortened line opens this summer.

What's so controversial about Flyvbjerg's research is not his documenting cost overruns. It's his effort to show why public projects are so chronically out of whack.

It's not technical challenges or complexity or bad luck, he asserts. If that were so, you'd get more variation in how it all turns out. He concludes the backers of these projects suffer from two main maladies.

One is "delusional optimism" — they want it so badly, they can't see its flaws. I know about this firsthand from when I supported the monorail.

The second is worse: They knowingly are lying to the public.

"Delusion and Deception in Large Infrastructure Projects," was the title of Flyvbjerg's most recent paper, published in January. He details through interviews with public officials how the pressure to get a project approved politically and under construction almost invariably leads to deception — a lowballing of costs and an exaggeration of benefits.

Which brings me back to our viaduct-replacing tunnel.

I have no idea if planners there have underestimated the cost of that tunnel. Some projects do come in on budget. We likely won't know for a year or more.

I do think it's suspicious that this same tunnel was rejected in December by a stakeholder advisory committee on account of it being way too expensive.

Only to have the costs then shrink (!) by $400 million, arriving at a size that happily fits the state's pre-existing budget.

Many aspects of the new tunnel seem to jibe, generically, with Flyvbjerg's recipe for a boondoggle. It has been minimally engineered. It has boosters spinning for it, in this case a Seattle think tank, the Discovery Institute. And there is extreme political pressure — or exhaustion — after eight years of dithering and delay.

Flyvbjerg chronicles many types of public deception, from the hard sell to the noble lie. Still, he has no example that tops a public official making a promise as categorical and unknowable as: "There will be no cost overruns."

Nobody seems to believe that pledge, even as they repeat it. Last week, the Legislature passed an amendment to put all cost overruns for this tunnel onto the property owners of Seattle. The project wouldn't pass without it, they said out of one side of their mouths. But don't worry, there won't actually be any overruns, they said out of the other.

I think they know this tunnel is going to cost more, probably far more. But everyone is sick of talking about it. I know I am. That they've finally made any choice at all seems like a victory.

Flyvbjerg says that's the way it often goes. He also has all sorts of ideas for how to make this process more honest and accurate, most involving outside scrutiny. Suffice to say, that route would drive up the estimated costs of most projects dramatically.

I wondered, when I read them: If we knew the truth, would we accomplish anything at all?

Or is it better to be lied to?

IDAHO Bridge Construction

Environmental impact will be a complicated issue as to construct the bridge

ST. ANTHONY - Environmental concerns for an endangered aquatic snail could hold up construction of a long-awaited bridge on a major farm-to-market route in Idaho.

The Utah Valvata snail is on the U.S. endangered species list, and county officials have been waiting to see if the mollusk would

further delay reconstruction of the Salem Highway bridge over the Snake River.

The Idaho Transportation Department had scheduled work on the bridge for this summer, but the chance the snail may be living near the bridge could delay the work.

The highway is a major farm-to-market route north of Idaho City, and is used by traffic heading in and out of Rexburg, Idaho.

Steel Solution for Viaduct Replacement

28 NSC March 2009
Bridges

Steel can be a solution for Viaduct Replacement in time to comes

The Wolvercote Viaduct in Oxfordshire is a vitally
important transportation structure as it not only
carries the A34 dual carriageway over the River
Thames flood plain, but also spans the Oxford to
Birmingham main line railway, the Oxford Canal as
well as the A40 Oxford to Cheltenham road.
Built in the early 1960s this strategic double
bridge viaduct has suffered extensive deterioration
due to the ravages of time and requires significant
and regular maintenance to ensure it remains safe.
Replacing a concrete viaduct with a new weathering
steel composite structure while ensuring minimal
disruption to the travelling public has presented
the construction and project design team with a
number of challenges.
One of the main objectives of the scheme is
to replace the existing 250m-long viaduct while
maintaining the current peak time traffic flows. To
achieve this a dual lane offline temporary viaduct,
capable of taking the A34 southbound traffic, is being
constructed adjacent to the existing southbound
bridge.
This offline viaduct will allow traffic to be diverted
off the existing northbound viaduct so it can be
demolished and a new structure built in the same
position. Once the northbound viaduct is constructed
the northbound traffic will be diverted back to its
original alignment.
This in turn will allow the project team to demolish
the existing southbound viaduct and construct
a new replacement structure in its place. This work
will essentially involve piling and then the installation
of new concrete piers.
“In order to reduce the project duration we will
then slide the 250m long x 11m wide offline viaduct
deck in to the original southbound viaduct alignment,”
explains Darren Dobson, Costain’s Project
Manager. “This jacking and sliding procedure will
take place in one night time shift in order to limit
the disruption to road users.”
The temporary southbound viaduct was begun in
the Summer of 2008, with piling work and piers cast
prior to steelwork erection beginning. The steel deck
was then completed in an eleven week programme
beginning in October.
“Although the southbound bridge is temporary
it still resembles a permanent structure and was
erected as such,” explains Simon Reavell, Project
Manager for steelwork contractor Fairfield Mabey.
“We have supplied interface plates which are placed
below the deck bearings, and they will aid the sliding
process.”
The 250m long temporary bridge has seven
spans, three fewer than the existing viaduct, and
was erected one span at a time. The length of each
of these spans vary, but they are all approximately
35m long. Fairfield Mabey brought the necessary
steel girders to site and assembled them into pairs
on the ground before lifting them into place. Each
span is made up of four main girders, which means
two pairs and two lifts per span.
The temporary southbound bridge is now nearing
completion. Once complete, traffic will be
switched on to the new structure allowing demolition
to start on the existing northbound bridge.
“The new northbound bridge is a similar
structure to the southbound bridge,” explains Mr
Reavell. “At 250m long and seven spans it will be
erected in the same way as the temporary off-line
bridge.”
Once demolition has been completed, Costain
will begin piling and then construct the bridge piers.
Steelwork for the second bridge is scheduled to begin
in July.
Meanwhile, the southbound temporary bridge
deck is scheduled to be moved onto its new piers
and abutments sometime in the Summer of 2010.
“Moving a 250m long deck, weighing in excess
of 5,000t, will be challenging manouevre,” says Mr
Dobson “But we anticipate moving the deck in one
six hour overnight phase.”
Once the deck has been slide to its new position,
the temporary bridge piers will be demolished leaving
no trace of it ever being there.
To keep vehicles flowing on the A34 near Oxford a temporary bridge will carry traffic while an
existing viaduct is demolished and then rebuilt. The deck of this temporary structure will later
be incorporated, after a sliding operation, into the new viaduct.
Steel solution for
viaduct replacement
FACT FILE
A34 Wolvercote
Viaduct
Main client:
Highways Agency
Main contractor:
Costain
Structural engineer:
Jacobs
Steelwork contractor:
Fairfield Mabey
Steel tonnage: 1,800t
Project value: £44.4M
Above: The Wolvercote
Viaduct spans road, rail
and canal.
Below: The initial
temporary bridge is being
built adjacent to the
existing viaduct.

The proposal of the railroad viaduct construction system utilizing the self-compacting high strength and high durable concrete.

A new innovation in viaduct Construction Technology

It will a revelation for the way we construct viaduct in the future

Title;The proposal of the railroad viaduct construction system utilizing the self-compacting high strength and high durable concrete.

Author;TAKEDA YASUSHI(Tekken Constr. Co., Ltd.) SAKANOUE HIROSHI(Aoki Corp.) SUMI HIROYUKI(Fujita Corp.) OZAWA KAZUMASA(Univ. Tokyo, Graduate School, JPN)

Journal Title;Kensetsu Manejimento Mondai ni kansuru Kenkyu Happyo, Toronkai Koenshu

Journal Code:X0097A

ISSN:

VOL.19th;NO.;PAGE.59-62(2001)

Figure&Table&Reference;FIG.7, TBL.3, REF.3

Pub. Country;Japan

Language;Japanese

Abstract;To convert from a minimum material to minimum manpower, the research of the structure which replaces a past beam slab type viaduct is actively done in the railway viaduct. Recently, it is necessary to increase a concrete quality and durability because the accident concerning the concrete of the tunnel and the viaduct occurred. Moreover, it is expected to become cheap in the life cycle cost though an initial construction cost of the self-compacting high strength and high durable concrete structure is comparatively expensive. Then, to establish the construction system utilizing the self-compacting high strength and high durable concrete, authors paid attention to the term of works shortening and the labor saving, and did the cost analysis of the railway viaduct. As a result, the structural type utilizing the self-compacting high strength and high durable concrete almost becomes equal with a past structure in an initial construction cost. Moreover, the structural type confirmed becoming in the life cycle cost the advantage by the high durability of the self-compacting high strength and high durable concrete. (author abst.)