Building Construction Engineering Civil Bridge Millau

2. THE WORLD’S TALLEST BRIDGE

3. This is the Bridge Which Faced Some Great
Engineering Problems From The Start Of The
Project
•This bridge was to be constructed over one of the
deepest valley of France, which had two major
engineering threats for the bridge.
1. Foundation Problems Caused By The Porous Lime
Stone
2. Major And Frequent Land Slides

4. So why construct a bridge with such
threats in the first place?
Because Of This
• A75 is the motorway that connects Paris to Spain. The
motorway goes right to the southern France where it meets
with one of the deepest valley of the France.
• A dead end.
• So, from here all the traffic was diverted to the small town
of Millau which caused a great problem for the residents of
the town.
• And after years of suffering to the locals finally the French
government decided to make a bridge over the valley.

5. •So the project was out.
•The worlds tallest bridge, 2.5 km
long was constructed.
•A great engineering achievement.
•Millau Viaduct.

6. IMAGINE BUILDING A SERIES OF EFFIEL TOWER ,AND
THEN LYING A FOUR LANE HIGHWAY ON IT . ACROSS
ONE OF THE DEEPEST VALLEY IN THE FRANCE.

7. The Millau Viaduct is a cable-stayed bridge that spans
the valley of the River Tarn near Millau in
southern France .It is the 12th highest bridge deck in
the world. Millau Viaduct is part of the A75-A71 auto
route axis from Paris to Montpellier

8. FOUNDERS of Millau Viaduct

9. Dimensions of the viaduct
Length : 2,460 m
Highest pier : 245 m (P2 )
Height of metallic pylons : 90 m
Slightly curved : constant radius 20KM

10. THREE DUANTING CHALLENGES THEY
FACED
1) BUILD THE TALLEST BRIDGE PIERS IN THE
WORLD
2) PUT 36000TON FREEWAY ON TOP OF IT
3) ERECT 7 STEEL PYLONS HUNDREDS OF
METER ABOVE THE SOLID GROUND

11. Construction Overview
• Temporary piers used to
help launch and support
the deck as the the pylons
were constructed.
• The 2460m deck was
launched in two pieces.
• Pylons and cables were
added on top of the piers.

12. THE PIERS

13. Each PIER is supported by four deep shafts, 15 m (49 ft)
deep and 5 m (16 ft) in diameter.
Top view of the P2 pier
close to
its full height
The crane is linked to
the pier and
raised in the same step

14. EACH PIER WAS COSNTRUCTED AT THE
SECTIONS OF 4 METER
• AFTER THE
CONSTRUCTION OF
THAT SECTIONS THE
MOULDS ARE
REMOVED
• THE CYCLE IS REPEATED
EVERY 3 DAYS FOR
CALIBRATING THE
MOULDS FOR NEW
SECTION

15. • THE MOULD IS NEEDED TO CHANGED AS THE PIERS HAVE DIFFERENT
CROSS SECTION THROUGH IT’S LENGTH
• THE VARITION IN CROSS SECTION OF THE PIER IS SHOWN
• THE TOTAL HEIGHT OF PILLERS COMBINED IS MORE THEN 1 KM , SO
THE MOULDS NEEDED TO BE RECALIBRATED OVER 250 TIMES

16. THE PROGRESS OF PIERS WAS MONITERED BT GPS
PIER 2 WAS NEEDED EXATLY TO BE AT
245 m from ground
546 m from south
1916 m from north

17. Completion of Pier Construction.
•Months after months the piers grew taller and in
November 2003 their construction was finished.
•Amazingly each pier was perfectly on its place,
dead on target.

18. Construction Innovation:
The Millau Viaduct Deck
Launch

19. STEEL DECKS
• THEY OPTED FOR STEEL DECK OVER THE
CONVENTIONAL CONCRETE BLOCK , AS IT’S NOT
ECONOMICAL AND SAFE TO LIFT CONCRETE OVER
SUCH HEIGHTS
• FABRICATION OF THE DECK SECTION WAS DONE ON
STEEL FACTORY
• AROUND 2200 SECTIONS EACH WEIGHING UPTO 90
TONS AND SOME WERE 22M LONG

20. TO OVER COME THE DIFICULTY TO SLIDE THE DECK
OVER THE SPAN OF 342M
• THE INTRODUCED STEEL
TEMPORARY TOWERS BTWEEN
TWO PILLERS BEACUSE THE SPAN
BETWEEN TWO PIERS WAS LARGE
AND DECK COULD NOT SUPPORT
ITSELF
• FIRST TWO PYLONS AND CABLES
ON BOTH THE END WHERE ON
THE SOLID GROUND BEFORE
SLIDING IT , TO GIVE THE DECK AN
ADDITIONAL STIFFNESS

21. Deck Launching
• 7 temporary piers help
support the weight of
the deck , as the
longest the deck could
support was half of
the span
• 2 deck segments were
launched from the
each end of the
bridge.

22. Hydraulic Launchers
• Computerized launchers
push the pre-fabricated
deck segments onto the
piers.
• Each cycle moves the
deck 600mm. Total of
5000 cycles required.
• THE CYCLE IS REPEATED
EVERY 4 MINUTES

24. Nose Recovery
• Weight of steel box-girder
deck sags as
span is completed.
• Nose recovery system
attached to raise the
deck to the level of
the next pier.
• This aligns the deck
for the level and
curvature of the next
pier

25. Completion of deck
• Two deck segments joined in May of 2004.

26. Pylon Construction

27. •After the deck construction
was finished it was time to
erect the pylons to provide
cable support for the bridge.
•The temporary piers were
supporting the deck but due
to the flexibility of the steel
the deck was very
undulating, the deformations
were quite large.
•So the 90 m tall and 700 ton
pylons were installed as fast
as possible.

28. Egyptian Technique
• Pylons and cables were needed to straighten the undulated
deck.
• For placing the pylons steel engineer Marc Buonomo used a
technique which was practiced in the ancient Egypt.

29. •In this Egyptian method the pylons were lifted
slowly using a hydraulic crane.
•As they were being lifted they were also made to
pivot by two temporary steel towers, both of them
secured by a cable.
•As the bridge is lifted it also pivots until it is
vertical and the it’s erected.

30. Attachment Of Cables
•With all seven pylons in place it
was time to attach the cable stays
that would straighten the rippling
deck and give it the strength to
endure the traffic load.
•The roadway weighs over 40,000
tons and the 154 cable stays should
prevent it from sagging or
collapsing.
•These cable stays are made of 91
individual steel strands and have
breaking strength of 25,000 tons.
•These stays are strong enough to
hold 25 jumbo jets all at full
throttle!

31. A Great Challenge Faced By Millau Viaduct
An issue that presented itself after the bridge was completed was the fact that the
wind speed at the level of the bridge was “up to 151 km/hr,” which is significantly
more than the wind speed that would be found at ground level. This would cause
serious issues driving on the bridge because the high wind speeds would push
vehicles to the side, making driving dangerous. This problem was addressed by the
inclusion of wind screens that reduce the affect of the “wind by 50%,” effectively
causing wind speeds on the bridge to reflect those on the ground.

32. The Wind Screens
Used to reduce the
speed of wind by 50%

33. •Intriguingly the Millau Viaduct is not straight. As a straight road
could induce a sensation of floating for drivers, which a slight curve
remedies. The curve is constant circular curve of 20km radius.
•Moreover the road has a slight incline of 3% to improve the
visibility.