Rio Antirio Bridge And Millau Viaduct Engineering Essay

Rio-Antirio bridge, the worlds longest suspension bridge, connecting Western Peloponnese with mainland Greece, 1998-2004 Millau viaduct. Millau, france, 1993-2004

Comparison:

The two bridges are both phenomenal suspensions bridges in their locations.

With taking into account the location of these two bridges, both bridges, Both are considered to be an architectural and engineering marvels.

Concrete plays an important role in the construction of suspension bridges. There will be massive foundations, usually embedded in the ground. There are abutments, providing the vital strength and ability to resist the enormous forces.

They both have exceptionally large dimensions and resistance to huge forces such as wind in Viaduct case and wave, wind, earthquake and many other natural forces, in Rio-Antirion case. Both bridges were constructed in a limited time constraint and both where successfully delivered on time.

The construction was a good opportunity for both countries to create jobs as well as profiting financially and economically from the structures. These two similar structures where created in two different locations, Rio-Antirio bridge in Greece was created over the gulf of Corinth, whilst the Millau viaduct Bridge in France was created over the valley of the river tarn.

Both bridges are very long thus the engineers decided to use suspension bridges. They both started construction at about same time.

Rio-Antirion in Greece was constructed by a French company, where as Millau-Viaduct in south of France and constructed by a British company.

Here are the differences and similarities of the two bridges in case of construction, economical, and many other aspects.

Rio-Antirion Bridge:

After 5 years of construction the Rio-Anitirio bridge was opened to traffic on 7th of August 2004

The Rio-Antirio bridge was constructed in Greece by a French company, Vinci. Greece needed the construction to be finished before the 2004 Olympics, which was not enough time for most of the construction companies. Also to make the matter worse the bridge had to be constructed on a river, meaning it had to have a high strength to resist the strong tides and earthquakes, as the location of this bridge is extremely prone to earthquakes and tide waves.

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The Greek government set the French company a fixed price and time to do the job as there was no time for a mistake, Considering these entire situation the French company still decided to go ahead and take the project. If the bridge was not ready by the deadline the French company had to pay a fine as well as the expenses for the construction from that point onwards.

The bridge meant much easier and faster transportation for Greek people as it connects the two major cities of Antirio and Rio together (Antirio and Rio, hence the name). In addition, it would be a valuable income for the Greek government economics. As it was close to 2004 Olympics which supposed to take place in Greek. Also because of the transport problem in that location a lot of people will be using the bridge, which meant they have to pay (cars: €11.70, motorcycles: €1.80, coaches: €26.20-€56.50 and trucks €17.30- €38.00). As the bridge connects Rio to Antirio which is in mainland Greece, thus connecting with the rest of Europe. The only means of transport between these two lands was by using ferry or via the isthmus of Corinth at its extreme east end, therefore this bridge was really important for the Greek transportation. The bridge reduces travel time across the straight from 45 minutes via ferry to less than 5 minutes.

Bridge construction:

The Rio Antirio Bridge’s pylons are made from reinforced concrete and pylon legs range from 25m to 45m above sea level.

“Seabed reinforcement was achieved by using inclusions, which are 2 m diameter hollow steel pipes 25 m to 30 m long. 200 pipes were driven in to the seabed by a crane on a tension leg platform, which was installed at every pier location; this was topped with a 3 m thick, levelled gravel layer. A cone with a diameter of 38 m formed the lower part of the pier.”5

The bridge is counted as one of the tallest and longest bridges as it consist of five cable stayed spans and four columns, the longest span is 560 meters. The bridge is 2880 meters long with a width of 27.2 meters across. The towers, particularly their foundations, are the real technical achievement of this project. The seabed on which the foundations rest was specially prepared in order to eliminate the effects of earthquakes.

The bridge consists of 6 lanes, 2 lane on each side, 2 emergency on each side as well as a pedestrian and bicycle lane .The total cost of the bridge was about € 630,000,000, funded by Greek state funds, backed by loans from the European Investment Bank.

During the construction, the French company decided to create a suspension bridge, as the distance was to great for any other type of bridge. They had problems before and during construction, such as; the site had difficulties including deep water, insecure materials for foundations, seismic activity, the probability of tsunamis, and the expansion of the Gulf of Corinth due to plate tectonics so this bridge is counted as one of engineer’s masterpiece. One of the major problems during the construction was, whiles installing a column the tides where too strong and placed the pile in the wrong position. As the company had no time to remove the column and replace it again as it was too heavy, it would cost them much more that they had planned so the engineers decided to move the whole process by the distance misplaced.

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The piers of the Rio-Antirio Bridge can slide on their gravel beds to accommodate tectonic movement.

Engineering feats

As the results of these problems, the engineers had to come up with a solution that is both strong and also flexible during earthquakes. “The water depth reaches 65 m, the seabed is mostly of loose sediment, the seismic activity and possibility of tectonic movement is significant, and the Gulf of Corinth is expanding at a rate of about 30 mm a year. For these reasons, special construction techniques were applied. The piers are not buried into the seabed, but rather rest on a bed of gravel, which was meticulously levelled to an even surface (a difficult attempt at this depth). During an earthquake, the piers should be allowed to move laterally on the seabed with the gravel bed absorbing the energy. The bridge parts are connected to the pylons using jacks and dampers to absorb movement; too rigid a connection would cause the bridge structure to fail in the event of an earthquake. It was also important that the bridge not have too much lateral leeway either so as not to damage the piers. There is provision for the gradual expansion of the strait over the bridge’s lifetime.”1*.

As result of the bridges enormous size and the risk this carries a yearly maintenance is need to be carried out to ensure the safety of the users.

On January 28th 2005, only six months after the opening of the bridge, as the result of a failure in one of the cables the bridge had to be closed to the public. As there where 4 more cables supporting this section of the bridge minimum damage was caused to the bridges core structure.

For health and safety there are more than 100 sensors installed on the bridges, which provides 24/7 surveillance of the structure.(JPG)

*-refer to reference 1.

Millau- Viaduct bridge

This bridge was constructed from 1993 to 2004 in southern France. Linking France and Spain by constructing a motor way over the River Tarn. The bridge has been constructed on a 2 km valley divided in two by River Tarn.

An English company foster constructed this bridge.

“The milau viaduct bridge not only has a dramatic sihoutte, but crucially, it also makes the minimum intervention in the landscape. Lit at night, it traces a slender ribbon of light across the valley”. Foster partners 2004.

Viaduc de Millau is the chosen solution for taking the A75 motorway from Clermont-Ferraud south to Beziers. This is cheaper than the alternative of tunnelling through the hills flanking the river, and will shorten the journey by 100 km and by up to 4 hours in the holiday season, as well as removing much traffic pollution caused by continual traffic jams for local inhabitants in Millau.

The government makes money by charging the vehicles using the bridge. The Milau Viaduct Bridge is also being used for extreme sports such as base jumping and repelling. Also is very economical as it saves a lot of time and avoids traffics.

The construction process involved approximately five hundred workers working simultaneously on the project, which means it was a good opportunity for France to create many jobs.

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This project was proposed by the owners ‘Compagnie Eiffage du Millau Viaduct’ (CEVM) and the client ‘SETEC’ to cross the Tarn gorges by a viaduct/ road bridge. All designs had to satisfy the design brief, but Fosters knew that this bridge posed several novel problems. Tests revealed problems for drivers on such a high, long and thin structure with just two lanes either sides.

The bridge is 343 m high and is a multi cable-stayed structure with slender piers and a very light deck, touching the valley at only seven points.

It was decided to design a multi cable-stayed bridge (2460 m long) because Lord Foster wanted the bridge to look as transparent and lightweight as possible to reduce cost, but also to attempt to minimise the effect of the structure in its environment as well as reducing wind loadings.

The solution was to incline the bridge by 3% to improve road visibility, and to make the whole structure curved to lessen the sensation of floating, even though this would increase the length of the bridge to 2.5 km and add to the cost. To prevent drivers from the distraction of the beautiful scenery, the hard shoulder on both sides was increased in width to three metres. Emergency phones were designed for every 500 metres along the full length on each side.Millau1

Viaduc de Millau

The construction consists of:

The deck- steels of grade S355 and S460

The piers- reinforcement concrete

The cables-steels of grade S355 and S460

The abutments- reinforcement concrete

The pylons- steels of grade S355 and S460

(the concrete was used more for its high durability as this bridge is estimated to last 120 years, rather than its high mechanical resistance.)

Construction:

The structure is continues along its eight cable spans. The two spans at each side’s are 204m and the six spans in middle are 342m each.

The bridge has 2 lanes and an emergency line at each side.

The construction method was beneficial.

The factory pre-production of certain parts of the deck reduced the volume of material that had to be worked on on-site, something which never would have been possible with an all-concrete structure. Less equipment, less construction material, fewer trucks going back and forth clogging up traffic in all it added up to less disturbance to the life of the local population.

The Millau Viaduct was described by Lord Foster as his “sculpture in the landscape.”The whole thing looks impossibly delicate,” Foster said in a telephone interview.

This bridge is one of the most popular tourist attractions in the France because of the exceptional dimensions and the natural grandeur of the Aveyronnais landscape.

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The deck consists of a trapezoidal profiled metal box girder and to ensure resistance to fatigue a thickness of 14 mm has been used for the whole length of the structure. The deck was designed prefabricated which speeds the process and also is environmentally friendly as it uses much less landscape during construction. The decks are supported by multi-span cables which are constructed from steel too.

There are eleven pairs of cables, which support each span. The cable anchors are adjustable at the deck end and fixed on the pylons.

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To install the deck successfully, seven temporary piers were needed. These temporary piers consist of a metal framework in the form of K. The top of each temporary pier is fitted with metal trimmer to receive the beginning supports, known as translators. The highest temporary pier was 173 m high.

The entire cost of creating this bridge was 320 million Euros. The bridge consists of eighteen cameras located at various locations on the bridge to ensure the bridge safety 24 hours a day. The cameras are connected to computers to monitor the bridge for traffic, wind loads and any damages that may happen to the bridge.C:UsersRaminDesktop4.jpg

The viaduct was ensured to have:

– Specially designed safety barriers that can withstand impact from heavy lorries.

– Transparent windbreak screens 3 m. high to limit the effect of the wind on vehicles.

– Emergency lanes 3 metres wide.

– Emergency phones every 500 metres.

Conclusion:

In conclusion, the Rio-Antirion is longer than Millau-Viaduct; however, Millau-Viaduct is considerably higher than Rio-Antirion.

The Rio-Antirion is cost approximately double Millau-Viaduct. The environment on which Rio-Antirion was build on can justify this. As more time need to be spend reinforcing the seabed on which Rio-antirion was being build on.

Millau-Viaduct is much more environmentally friendly than Rio-Antirion.

Both bridges meant an easier and faster way to travel that saves a lot of time. As well as reducing the traffic load on other means of travelling the same distance.

Both bridges have similar structure but constructed in different methods. Rio-Antirion was constructed separately on each pier and then reaches to each other. However, Millau-Viaduct was constructed from both ends and reach together in the middle. Each of this methods where chosen as it best suite the environment on which the each bridge was being build on.

The Millau-Viaduct was prefabricated in the factory to ensure limited landscaped is used on the site, thus environmentally friendly.

Rio-Antirion was constructed much quicker than Millau-Viaduct hence explains the costs. In addition, Rio-Antirion had alot more problems in terms of site location than Millau-Viaduct in case of engineering. Rio-Antirion was constructed completely in water, which increases the expenses as engineers needed to use a specially designed ship to transport the ready made piers to their specific location. The ship had to be hired from another country as the piers were very huge and heavy and Greece did not have any ship capable of handling the weight of the piers.