Analysis of Eiffel tower, Structural Details, artistic details, maintainence details

1. Seminar
Presentation
2K’17

2. By:
Aaditi Dhyani
ID No. :
140501
Civil Engineering
(3rd Year)

3. A Presentation on
Eiffel Tower
An in-depth analysis of
the Iron Lady.

4. Contents:
i) Introduction
ii) The Builder
iii) Construction
iv) The structure
v) Structural Analysis
vi) Maintenance
 Conclusion
 Reference

5. INTRODUCTION

6. • Built for World’s Fair and to
celebrate the centennial of the
French Revolution.
• The tower officially opened May 5,
1889.
• “The Iron Lady” was the star
attraction with 2 million visitors.
• It symbolizes ideals of ingenuity,
progress, and beauty.
• It was the tallest structure in the
world until 1930.

7. The
Builders

8. Gustave Eiffel, a renowned civil
engineer of that time, known
from his revolutionary bridge
building techniques is usually
credited with the building of the
Tower.
He was also known for the
construction of the statue of
liberty’s iron framework, the
Maria Pia bridge or the Garabit
Viaduct.

9. Civil Engineer
Émile Nouguier
Architect
Stephen Sauvestre
Civil Engineer
Maurice Koechlin

10. Arches added to the
design by Stephen
Sauvestre.
Original pylon
design by Koechlin
and Nougier.

11. The
CONSTRUCTION

12. Work began in January
26th,1887 with the digging of
the tower’s foundations,
which were laid in four
months.

13. The actual metal work
started on July 1887.

14. The Eiffel Tower’s base is composed of four legs. In these legs are 2
anchor bolts that are each 26 feet long and 4 inches in diameter. One
part of Eiffel’s plan for the foundation of the structure was the
placement of a hydraulic jack. The hydraulic jack was used to enable
the raising or lowing of the platform to make certain it was level.

15. All the elements were prepared in Eiffel’s factory in Levallois-Perret
on the outskirts of Paris. Each of the 18000 pieces used to construct
the tower was specially designed and calculated, traced out to an
accuracy of a tenth of a millimetre and then put together to form new
pieces, each measuring about 5 meters.

16. On site a team of builders, was
responsible for the 150-300
workers who assembled the
gigantic structure.

17. All the metallic pieces on the
Tower were fixed by rivets. This
was a well known technique at the
time of the construction.

18. A team of four men was needed for each rivet
assembled: one to heat it up, another to hold
it in place, a third to shape the head and a
fourth to beat it with a sledgehammer.

19. The tower is built with
wooden scaffolds and small
hoists directly fixed to the
tower.

20. Beginning of second
floor- June 1888.

21. Above the second floor-
September 1888.

22. Above the middle floor-
December 1888.

23. The workers, perched on a
ramp just a few centimetres
wide, at a steep height for the
topmost floor of the tower.

24. It took just two years two
months and five days to
build the Eiffel Tower, a
record speed considering
the rudimentary means
available at that time.
The construction work
was finished on 31 march
1889.
The assembly of the
tower was a marvel of
precision.

25. The
Design

26. Puddled or wrought iron.
• The metal structure weighs
7,300 tons.
• Total weight:
10,100 tons.
• Number of rivets used:
2,500,000.
• Number of iron parts:
18,038.
• Cost of construction:
7,799,401.31 French gold
francs of 1889.
MaterialUsed

27. Gustave Eiffel created a two-system foundation for the Eiffel
Tower, to protect the reinforced concrete structure from
flooding through the Seine river (near the North and East
pillars).
Foundation

28. Top Platform
First Platform
Second Platform
Ground Level
Height – 324 m
1430 sq. m.
CROSS SECTION
4415 sq. m.
250 sq. m.
276 m.
115 m
57 m
Dimensions

29. VerticalTransport
In June 1889, five hydraulic elevators were installed for the
use of visitors. Maintained regularly, they cover a distance
equal to two and a half times around the world.

30. VerticalTransport
A staircase going to the top, has a total of 1792 steps,
commemorating a centennial of French Revolution.

31. Structural Analysis

32. Loads
Three types of loads act on
the Eiffel Tower:
1. Dead load- its own weight
2. Live load- the weight of
people and machinery.
3. Wind load
Live Load: A live load of 50
pounds per sq. ft. is taken for
the tower.
Dead Load: The net weight of
the tower is divided into three
sections, as shown in the figure.

33. This live load acts in combination with the dead load for a total
vertical load of:
This load acts through the centroid of the Tower, which is located 257
feet above the ground.
Wind Load- Along the height of 984 feet, the total force is:
The centroid of this force is halfway up the Tower so P, the idealized
point wind load, acts at this point.
Loads

34. Reactions
The overall reactions at the base of the Tower are
easily found from the wind and gravity loads (dead
and live). Overall vertical and horizontal reactions
will develop to balance the respective loads. A
moment reaction will also develop to balance the
horizontal load applied through its centroid a
distance l/2 from the support.
The reactions at the base of each column, instead of
for the Tower as a whole, are necessary to find the
internal forces in the individual columns.

35. Reactions
Each column will logically develop half
of the horizontal and vertical reactions
found for the entire structure.
The wind force will create a
higher vertical reaction in
the leeward support and a
lower vertical reaction in
the windward support
because the wind alone
would create compression
in the leeward support and
tension in the windward
support.

36. InternalStresses
The values of compressive and tensile stress
can be found from the formula:
where the force, N, is the total axial force
found from both vertical and horizontal
loads.
The area of each of the two simplified
columns is 1600 square inches.
The compression forces found at the bases of
the Tower’s columns are N = -7,630 kips on
the windward side, and N = -15,780 kips on
the leeward side.

37. InternalStresses
The resulting stresses are:
on the windward side and:
on the leeward side.
Because the wind may act on the Tower
from any direction, each of the supports
must be designed to take the maximum
stress of -9.9 ksi.
This is also a rough estimate of the maximum stress on each of the
actual Tower’s four columns, because the idealization has combined
four columns into two twice as large.

38. Safetyfactor
The safety factor for the Eiffel Tower is the
ratio of the ultimate stress and the actual
stress. The ultimate stress for iron is about 45
ksi. This is the maximum it can withstand in
both tension or compression before it fails or
breaks. The value of actual stress, -9.9 ksi, is
used with the ultimate stress, 45 ksi, in the
safety factor formula:
Structures are usually designed with at least a
safety factor of two, i.e. only half a building
material’s maximum strength is used.
Load>4.5 times the actual load

39. Efficiency
In design, one wants a structure not only to be strong,
but stiff, so that deformations cannot occur. If a
structure is stressed to the allowable limit, the safety
factor is found as usual:
The safety factor for wrought iron is about three, so
the allowable stress is:
An ideal structure has an efficiency of 1.0 or 100%
where actual stress equals the allowable. The Eiffel
Tower, with a maximum stress of 9.9 ksi, has an
efficiency of:
The actual structure has a factor of four and a half
while the material could withstand a factor of only
three.

40. MAINTANENCE

41. Weight of paint-
approximately 60 tons
Time required-
15 to 18 months
Frequency required-
every 7 years.
No. of workmen-
25 painters
Cost of painting (approx.)-
3 million euros
Colour-
Bronze

42. Conclusion
 The Eiffel Tower and it’s daring
design were quiet ahead of it’s time.
Gustave Eiffel received the highest
accreditation for the construction of
the tower, when it was renamed after
him.
 Numerous aerodynamic researches
have been performed on the tower.
 The massive height of the tower has
been useful in the field of telegraphy
and telecommunication.