Millau Live!!!

Here is a link to a Live Web-cam feed of the MILLAU VIADUCT .Click here to visit. You can also find Cam-feeds for other famous places.

LAY man's SAY

Sam Lee's article just exemplifies the revolution in architecture.It is not the culmination of evolution of Technology, yet ,man's ambition is audaciously undeterred to challenge even Mother Nature. I am overwhelmed at the fact that we have the technology to actually put Non Linear Dynamic analysis to use .In fact,it is being used in some very important upcoming buildings as mentioned in the article. Although the calculation discussed in the article is beyond my reckoning, I have strove to understand the gist of the article and the importance of it.I would really like to understand more about it from a lay person's perspective. I had expected to get an idea about the sequence of the steps involved in using Non Linear Dynamic analysis but I am afraid I didn't quite follow that. I would also like to question Sam Lee that how safe the already built skyscrapers of USA and other countries are and what could be done to make them safer and more stable to earthquakes.

Construction Facts

• Two major obstacles faced in building this Megastructure were crossing the River Tarn, and spanning the huge gap from one plateau to the other. The solution proposed is unique- to use seven pylons instead of the usual two or three.

• SETEC’ approached the British Architect Sir Norman Foster to design a bridge to last 120 years.

• Tests revealed problems for drivers that how could the journey time be only about a minute using such a high, long and thin structure (just two lanes either way). The solution was to incline the bridge slightly (3%) to improve road visibility, and to make the whole structure curved (The curve is 20km in range;to lessen the sensation of floating) — even though this would lengthen the bridge to 2.5 km and add to the cost.Please note: The red towers in the picture were removed after completion of the Bridge.
  

• To prevent drivers from the distraction of the beautiful scenery, the hard shoulder on both sides was increased in width to three meters.

• Emergency phones were designed for every 500 metres along the full length on each side.

• It has been designed to look as delicate and transparent as possible. It uses the minimum amount of material, which made it less costly to construct,light and decreased the wind load : the deck, the masts rising above the road deck and the multi-span cables are all in steel.
• The steel deck was pre-constructed in 2,000 pieces at Eiffage’s Lauterbourg factory in Alsace and GPS-aligned, 60cm at a time.The factory was given just 20 months to supply the elements for the deck and the piers of the viaduct.

• To accommodate the expansion and contraction of the concrete deck, there is 1m of empty space at its extremities and each column is split into two thinner, more flexible columns below the roadway, forming an A-frame above the deck level.

• A 3m-wide emergency lane provides increased security. It will, in particular, prevent drivers from seeing the valley from the viaduct.

• As the bridge is exposed to winds of up to 151km/hr, side screens are used to reduce the effects of the wind by 50%. The speed of the wind at the level of the road therefore reflects the speed of the wind found at ground level.

• Construction work used approx. 127,000m³ of concrete, 19,000t (tonnes)of steel-reinforced concrete and 5,000t of pre-constraint steel (cables and shrouds). The project needed 205,000t of concrete, of which 50,000m³ will be reinforced concrete. In total, the viaduct weighs 290,000t.

• An 18-lane toll station 6km north of the Millau Viaduct is housed under a structure made of a special concrete patented by the group Eiffage.

Features

• The Millau Viaduct is supported by seven concrete pylons,each range in height from 77 to 246 m, and taper in their longitudinal section from 24.5 m at the base to 11 m at the deck. Each pylon is composed of 16 framework sections, each weighing 2,230 tons. These sections were assembled on site from pieces of 60 tons, 4 m wide and 17 m long, made in factories in Lauterbourg and Fos-sur-Mer by Eiffage.

• The seven masts, each 88.92 m high and weighing around 700 tonnes, are set on top of the pylons. Between each of them, eleven stays (metal cables) are anchored, providing support for the road deck.

• The metallic deck, which appears very light despite its total mass of around 36,000 metric tonnes, is 2,460 m long and 32 m wide. It comprises eight spans. The six central spans measure 342 m, and the two outer spans are 204 m.

• To allow for deformations of the metal deck under traffic, a special surface of modified bitumen was installed by research teams from Appia. The surface is somewhat flexible to adapt to deformations in the steel deck without cracking, but it must nevertheless have sufficient strength to withstand motorway conditions (fatigue, density, texture, adherence, anti-rutting, etc.). The "ideal formula" was found only after ten years of research.

• The pylons, deck, masts and stays are equipped with a multitude of sensors. These are designed to detect the slightest movement in the viaduct and measure its resistance to wear-and-tear over time. Anemometers, accelerometers, inclinometers, temperature sensors are all used for the instrumentation network.

Construction Timeline




Crossing The Millau Viaduct

le Viaduc de Millau

Standing Tall across the valley of the River Tarn near Millau in southern France, this grandiloquent cable stayed bridge traverses the Tarn valley above its lowest point, linking the Causse du Larzac to the Causse Rouge.This is the Millau Viaduct (French: le Viaduc de Millau).This Megastructure,which is the tallest vehicular bridge in the world with a mast summit of 343 meters,was designed by Norman Foster of Foster and Partners, and bridge engineer Michel Virlogeux. It is slightly taller than the Eiffel tower and falls short of 38m to the Empire State Building.Construction started in 2001 and it opened for use in December 2004.This gargantuan structure has an incredible length of 2460m.

"The Millau Viaduct is a magnificent example, in the long and great French tradition, of audacious works of art, a tradition begun at the turn of the 19th and 20th centuries by the great Gustave Eiffel," [President of France Jacques Chirac] told a reception.