Ponts des Arts Bridge

The Ponts des Arts Bridge is known by most people, especially tourists, as the bridge of Loveeee. Ever since the bridge was built, couples in love would write their names on a lock and lock it to the bridge gates, declaring their love to the world and making it everlasting in history. Sorry, I’m trying not to gag at the cheesiness. Talk about PDA. Anyway, the locks were removed in 2014, but the bridge still stands as the bridge of love to those who visited it. What most people don’t realize is that this bridge carries far more cultural significance than the locks. Technically this bridge is the second Ponts des Arts bridge, but since it is meant to replicate the original as closely as possible, the importance still stands. The original bridge was a symbol of France’s competition with Britain, and Napoleon ordered the original bridges creating personally. So, can we please move away from the love and focus on the interesting stuff? Because the both the past and present Ponts des Arts bridges are nothing if not interesting.

Figure 1: Ponts des Arts Bridge [1]

Structure Information

Okay, now we can get down to the basics, so stick with me.

Location: River Seine, Paris, France

Purpose: Connects the Louvre to the Insitut de France

Type: Deck arch pedestrian bridge

Main Material: Steel

Abutment and Piers Materials: Reinforced Concrete dressed in stone

Deck Material: Timber


  • 7 arches
  • 6 piers
  • 2 abutments
  • Deck
  • Deck gates

Total Length: 509’

Arch Span Length: 72’

Width: 36’

Figure 2: Ponts des Arts Close Up


As I mentioned in my introduction, this is the second Ponts des Arts bridge. The first bridge in some ways is more historically and structurally significant because it was the first iron bridge in France, and Napoleon wanted it to compete with the Iron Bridge, the first bridge made of iron in the world. However, the bridge that currently stands is modeled to resemble the original, but has two main differences that must not be confused:

  1. The CURRENT bridge is made of STEEL. The original bridge was famous for being made of cast iron in the early 19th century, but since steel is much more efficient and widely used now and when the current bridge was built in the 1980s, it is made of steel, NOT IRON.
  2. There are SEVEN arches on the CURRENT bridge. The original bridge had nine arches, but when remaking it, they decided that it would fit in more with its neighboring bridges over the River Seine if it only had 7 arches.

Historical Significance

To properly explain the significance in terms of technology, I have to address both the original bridge and the current one. The original bridge was much more innovative for its time being the first even iron bridge in France and one of the first few in the world. It was far more lightweight and elegant when compared to the Iron Bridge

or other stone arches at the time.

Figure 3: Original Ponts des Arts Bridge circa 1804 [2]

Figure 4: Iron Bridge [3]

Every member of the Ponts des Arts held a purpose and it efficiently used material, whereas the Iron Bridge was designed to show off its designer’s iron working skills, not its efficiency as a structure. So, the original Ponts des Arts Bridge is extremely historically significant and could be considered structural art in its own right.

Now moving on to the current bridge and the subject of this blog, this bridge is not as historically significant in terms of technology. However, since it does make adjustments like using steel instead of iron and forming fewer arches, it can still be seen as historically significant in regards to a better version of the original. It is not however the first of its time to use steel or anything like that.


Cultural Significance

The Ponts des Arts bridge is massively culturally significant for three reasons. The first being that it is a replica of the original bridge which was a statement of French power and engineering competition. So, while the first bridge was destroyed, its symbolism is renewed and everlasting in the current bridge. So Yay.

Secondly, this bridge is hugely popularized as the bridge of love, and is known worldwide through movies, popular culture, writers’ and painters’ depictions, and celebrity social media to people. So, not surprisingly, the decision to remove all of the locks and place glass in their place so that no additional locks could be added was extremely controversial. Being the dork that I am, I think the glass better highlights the structural prowess (and yes, I just used the word prowess) of the bridge which was obscured and came in second to the wall of locks that stood before. But I by no means represent to universal person; I don’t even really represent the normal person considering I like to look at and analyze structures for fun, so I can see why this is a big deal to people. But, as a structural engineer, any additional and unnecessary weight (especially one that equals 50 tons) should be added if it takes away the structure’s ability to fulfill its primary function: to resist natural forces. If part of the bridge collapses, because of the locks, the locks have got to go. But like I said, many don’t agree with me, so this has been somewhat of a hot topic since the bridge gate collapsed in 2014. In fact, when you search the bridge on Google, headlines after headlines come up that look like the one below.

Figure 5: Lock Gate Collapse Headline in Independent Co [4]

Despite all of this, the bridge still is popularized by tourists, locals, and artists alike because it stands at the core of Paris’ draw and art center. And to mitigate the anger, Paris auctioned off the love locks and donated all of the proceeds to a charity for migrant workers and refugees, which I have to say is pretty fricken awesome! So don’t feel bad if your lock was removed, because it was for a good cause and we can now happily move on.

So, lastly, this bridge is popular simply because of what it connects: the Louvre and the Insitut de France. Tourists and students can be seen not only walking on it (which, duh because it’s a pedestrian bridge), but Ponts des Arts is also a common picnicking location, the site of different art exhibitions, and a hub for local artists to make money off of tourists (which can be quite annoying having just been harassed by street vendors in Paris). Nonetheless, the bridge is still widely loved both around the world and locally.


Structural Art

Now, let’s take a look at Billington’s Three Es (probably dreaded by those of you who have read of these over and over again, so sorry): efficiency, economy, and elegance.


This bridge is extremely efficient. It uses very little material, reduced the number of arches to seven instead of the original nine, and is very transparent.

Figure 6: Structural Transparency


When passing under it, you can see all of its members, which are not that many, especially when compared to the other bridges around it made of stone. However, stone is used to hide the reinforced concrete on the abutments and piers, which is inefficient. Nevertheless, this bridge is efficient in its design and utilization of steel as a material in its own right. The form fits the material.


For some reason, the exact cost of construction of the Ponts des Arts is extremely difficult to find. But not to worry, we can use look at its use of material to gauge its economy. As stated above, the bridge uses very little steel in the superstructure, but uses extra material in the abutments and piers. Since stone is unnecessarily added to the reinforced concrete, that choice is not economical, but the superstructure is economical. So, I’d say that this bridge achieves half credit in the economy category.


This bridge is extremely elegant. For one, it is just plain pleasant to look at. But in terms of Billington’s criteria, the load path is clear in how it travels from the deck to its foundations, it is transparent and uniform in its design throughout the bridge. The stone abutments are a bit bulky, but in my opinion do not take away from the overall aesthetic of the bridge. So, without a doubt, I would say this bridge is elegant.

When taking all of the aforementioned factors into consideration, I would say that this bridge is structural art, although not the best example of it due to the piers and abutments. While casing the reinforced concrete abutments in stone was purely architectural, the elegance seen in the actual superstructure of the bridge overpowers that and wins for structural art in the end.


Structural Analysis

As stated above, this bridge functions like a typical arch bridge, with redundant arches next to each other to help with horizontal thrust. The spandrels also form semi-arches with diagonal bracing to help stiffen the deck and distribute the load throughout the arches rather than all at one point. This prevents the arches from buckling, almost as a flying buttress would. The load path, as demonstrated in the diagram below, starts at the deck as a combined uniform live and dead load, moves down into the arches either at the top of the arch or first into the spandrels and then into the arches. The load then transfers to the piers, which send the load down below water level and into the river bed.

Figure 7: Load Path


As any other typical arch, all of these arches are in compression, that is an arch’s defining characteristic. The spandrels are in tension, connecting the deck to the arches, each side pulling on the spandrel. The piers are in compression because they act like columns, with the load from the bridge pushing down and the normal force from the river floor pushing back up against the pier.

Figure 8: Members in Tension and Compression


We can use the principles of equilibrium to determine the forces acting on each member. To simplify the model, the following assumptions are being made:

  • Assume Deck is one solid surface
  • Assume pedestrian live load = 85 psf
  • tdeck = 1” = .083’
  • ρdeck= 35 lb/ft^3
  • ρsteel=490 lb/ft^3
  • Assume piers are made only of reinforced concrete with no added stone dressing
  • ρconc=115 lb/ft^3
  • Width of pier = 2’
  • Depth of pier = 31’

There are 5 arches in each span and 7 spans in the length of the bridge. So, for each arch:

The arches are made of steel which also have a dead weight. The free body diagram for each arch is the same and can be seen below. Note that the horizontal force that counteracts the arch’s thrust is either the thrust from the juxtaposed arch or from the abutment. Either way, the value should stay the same in order to achieve equilibrium.

Figure 9: Arch Free Body Diagram

The horizontal reactions caused by the thrust of each arch cancel each other out, and therefore do not require any extra calculations.

Moving onto the piers, each of the 6 piers in the middle hold a reaction from the arches on either side of it, and extend the width of 5 arches. So, each pier must support 10 times the point load coming from the arches. The free body diagram for the pier is shown below.

Figure 10: Pier Free Boody Diagram

There are 6 piers, so the bed of River Seine is actually supporting 6 distinct surface loads all equaling 5,714.64 psf.

The reason the reaction at the ground has units of force per area is because it is a surface load acting over the bottom of the pier, which has a length of 36’ and a width of 2’.


Personal Response

Okay, so this is probably more of a side effect to the program and having the three E’s drilled into my head continuously, but I can honestly say that my reaction when taking the boat tour and passing under the Ponts des Arts Bridge was “damn, that’s a piece of structural art”. While I ended up doubting that more when I took the time to analyze it as I did above, I just really admired how I could see the load path so clearly and it was so transparent. I didn’t even realize it was the love lock bridge I had seen so many times in movies, but clearly taking away the locks brought out the real character of the bridge rather than distracting from it.



[1] https://structurae.net/structures/pont-des-arts-1984

[2] https://en.wikipedia.org/wiki/Pont_des_Arts#/media/File:Paris,_Pont_des_Arts_by_Neurdein,_c1885-90.jpg

[3] https://www.shropshirestar.com/entertainment/telford-entertainment/2018/04/16/let-there-be-light-restored-iron-bridge-to-open-with-permanent-illumination/

[4] https://www.independent.co.uk/news/world/europe/part-of-paris-bridge-collapses-under-weight-of-love-locks-left-by-tourists-9512594.html

[5] http://www.eutouring.com/pont_des_arts_history.html

[6] https://www.napoleon.org/en/magazine/places/pont-des-arts-bridge/

[7] https://www.cometoparis.com/paris-guide/paris-monuments/pont-des-arts-s959

Musée d’Orsay

Structure Information

Gare d’Orsay, Paris, France, 1900                                                    Musee d’Orsay, Paris, 1986

Figure 1. Gare d’Orsay [1]

Figure 2. Musee d’Orsay









In 1900, Gare d’Orsay was built as a new central railway station for the World’s Fair in Paris [2]. The new station, and its integrated hotel, needed to blend in with its architectural surroundings [2]. Three architects, Lucien Magne, Emile Bénard and Victor Laloux, were consulted by the owners, the Orleans railroad company, who chose Laloux’s design in 1898 [2]. With changing times, the station served many purposes and in 1975, it was proposed to be renovated into a museum [2]. The new museum would serve as a connection between the Louvre and the National Museum of Modern Art [8]. ACT Architecture transformed the station into the museum it is today with interior design by Gae Aulenti and financial support from the French government [2]. As mentioned previously, the Orleans railroad company was the original owner and funded the original construction [2].

Historical Significance

Because of its need to blend in with its surroundings, the station has a Baroque style façade, incasing its use of the modern materials, glass and iron [3]. The station shows Laloux’s use of cast-iron arches that allowed for larger openings and a glass façade [4]. This use of cast-iron was innovative for its time.

The renovation of the station to a museum was unique because the original roof was kept intact [5]. Keeping the roof when renovating is rare because the roof is more susceptible to damage from moisture and sun [5]. Because the roof was kept, modifications had to be made to the construction techniques that would have been used. One of the major changes was using smaller, more compact equipment instead of a tower crane [5]. In addition to equipment constraints, it was important to make sure the construction did not cause vibrations.

The Gare d’Orsay was a model for Penn Station in New York [6]. The president of the Pennsylvania Railroad, Alexander Cassatt, was inspired by the station when he traveled to Paris in 1901 [6]. Penn Station was built in 1910.

Gare d’Orsay’s architect, Laloux, was also a professor. One of his students was William Van Alen, architect of the Chrysler Building [4]. While Laloux’s Gare d’Orsay may have been the model for only one structure, his teachings contributed to a world-known skyscraper.

Cultural Significance

Originally on the site of d’Orsay was the Palais d’Orsay, completed in 1838 [7]. It was the home of the Court of Accounts and the State Council [7]. In the Paris Commune of 1871, a revolt against the government, the Palais d’Orsay was burned to the ground [7].

As mentioned previously, Gare d’Orsay was built in anticipation of the World’s Fair in 1900, but by 1939, the platforms were too short to accomodate for the modern, longer trains and the station only provided serve to the suburbs [7]. After 1939, the station served as a mailing center for packages going to prisoners of war during World War II [7]. By 1958, the station was no longer in operation [7]. The rail station’s hotel shutdown in 1973 [7]. The hotel is historically significant because it was the location of General Charles de Gaulle’s press conference that announced his return to power in 1958 [7].

By 1973, the Directorate of the Museums of France was considering converting the station to a museum [8]. There were also plans to demolish the building and build a hotel in its place, but the station’s architect led it to be added to the Supplementary Inventory of Historical Monuments in March 1973 and classified as a Historical Monument in 1978 [7]. In 1986, the museum was inaugurated by President Francois Mitterrand [7].

In 1900, the painter, Edouard Detaille, wrote “the station is superb and looks like a Palais des beaux-arts…” [7] At the time, the station was considered beautiful. Today, it is perceived the same way. While the station is home to the largest collection of impressionist and post-impressionist paintings, reviews from TripAdvisor show that the conversion of the old rail station into a museum is what impresses everyone. Even the people crazy enough to give the museum a 1 star review compliment the building’s architecture! Musee d’Orsay provides a unique museum experience because of the preservation of its rail station history.

Structural Art

Structural art demonstrates efficiency, economy, and elegance. If the structure’s load path can be seen, the structure is efficient. In Musee d’Orsay, the load path can be seen relatively clearly on the inside but is hidden by a stone façade on the outside. Even on the inside, the walls are decorated with ornamentations that only add to the building’s architecture. These added decorations reduce the efficiency and economy. The building used 12,000 tons of metal in its construction, which is more than was used in the Eiffel Tower [8]. In addition to the original building lacking economy, the renovations were 3 years behind schedule and millions of francs over budget [7]. Based on the positive public opinion of the building, it can be said the building has elegance. However, a lot of this “elegance” is from architectural ornamentation, rather than the beauty of the structure itself. While the building is beautiful, it is not considered structural art.

Figure 3. Outside of Musee d’Orsay

Structural Analysis

Figure 4. Construction of stone façade [10]

Laloux’s design for the building stemmed primarily from the need to create a rail station that would serve the future while blending in with its historical surroundings. Thus, the glass and iron arches of the main hall are covered by a stone façade. Stone structures were added to the building’s interior to help create the museum’s atmosphere [9]. These structures hold their own weight. While the construction process is unknown, assumptions can be made from construction pictures. The stone façade was constructed using scaffolding before the arches were built. Next, the arches, interior façade, and glass were all added. For the renovation, scaffolding was installed throughout the building to gain access to the high roof. Figure 6 shows the arch construction.


Figure 5. Renovation [10]

Figure 6. Arch construction






The structural system of the building is a cylindrical arch system. Most of the loads on the structure are carried by its arch system.

Figure 7. Exterior Load Path

Figure 8. Cross Section Load Path

The structure carries load by transferring self weight to the arches which transfer load to the ground. In cases where there are no arches, the weight is transferred to columns. The cross sectional arches connect to the outside arches at their supports. Horizontal iron members connect the cross sectional arches and provide bracing. Each end arch in the main hall has interior beams and columns that provide extra support and bracing.

To analyze the structure, I am going to focus on the three arches over the building’s cross section. The building is 75 meters wide and 180 meters long while the main hall is 40 meters wide and 32 meters tall [2]. The whole building has 12,000 tons of iron and 35,000 square meters of glass [2]. Assuming the glass is 10 millimeters thick, the glass weighs 25 kg per square meter [11]. The density of iron is around 7400 kg/m3  and has an approximate diameter of 15 mm [12]. Limestone has a density of around 165 kg/m3. When the densities were converted to line loads, they were also converted from kilograms to newtons, and then to kilonewtons because of their magnitude. With a width of 10 m and an approximate thickness of 0.5 meters, the distributed load of the stone is 8.085 kN/m. The building has 8 main arches with smaller arches in between. Each main arch is around 10 meters wide and the span between each main arch is around 20 meters. Figure 9 shows the tributary areas of the arches. The white areas show the main arches. Each tributary area will be used to determine the weight of glass and iron acting on each arch.

Figure 9. Tributary Areas for the main arches

Using the above data and approximations, arches 1 and 8 have a distributed load of 10.66 kN/m. The other arches have a distributed load of 13.24 kN/m. The following diagrams and calculations were used to determine the force in each column due to the arches. Summing the forces in the x direction and y direction confirm that the forces in all of the arches balance out.

Figure 10. Forces in arches 1 and 8

Figure 11. Forces in arches 2-7

Figure 12. Calculations

Gare d’Orsay was a design competition won by Victor Laloux. He had recently completed a rail station and hotel in Tours and was able to successfully integrate the building with its surroundings [7]. Laloux would have used blueprints like the one in Figure 13 to explain his idea to the Orleans rail company.

Figure 13. Gare d’Orsay blueprint [10]

ACT Architecture was chosen to renovate the station by the French president, out of six proposals submitted [7]. ACT Architect used models like the one shown in Figure 14 to explain how renovations would work around the existing building. Figure 15 may have been a cross section used to explain how art would be laid out throughout the museum.

Figure 14. Museum model [10]

Figure 15. Museum layout schematic [10]

Gae Aulenti, the museum’s interior designer, was also an integral part of the renovation. Figure 16 shows a schematic of a cross section of the museum’s interior design.

Figure 16. Museum interior design [10]

Personal Response

The first time I visited the Musee d’Orsay, I was overwhelmed by the amount of beauty contained in one building. While the paintings and sculptures were impressive, I spent a good portion of my time admiring the soaring arches that rose above me. When I needed a break from looking at paintings, I had the enormous structure to dazzle me. Visiting the museum a second time only renewed my love for the structure.


  1. http://paris-historic-walks.blogspot.com/2012/12/musee-dorsay.html
  2. http://www.musee-orsay.fr/en/collections/history-of-the-museum/home.html
  3. https://www.britannica.com/art/Western-architecture/Classicism-1830-1930#ref489557
  4. https://study.com/academy/lesson/architect-william-van-alen-chrysler-building-works-biography.html
  5. https://www.tandfonline.com/doi/full/10.1080/15578770802229466?scroll=top&needAccess=true
  6. https://www.revolvy.com/topic/Gare%20d’Orsay
  7. http://discoverfrance.net/France/Paris/Museums-Paris/Orsay.shtml
  8. http://justfunfacts.com/interesting-facts-about-the-musee-dorsay/
  9. https://www.britannica.com/topic/Musee-dOrsay
  10. https://artsandculture.google.com/exhibit/ARK7SK5T
  11. http://www.leadbitterglass.co.uk/glassroom/calculate-weight-of-glass/
  12. https://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html

Walkie Talkie

Structure Information

Figure 1 – Picture by Me

Figure 2 – Picture by Someone Else

20 Fenchurch Street, known as the “Walkie Talkie,” was designed by Rafael Viñoly Architects and CH2M Hill structural engineers for Land Securities plc and Canary Wharf Group plc. This skyscraper, used as office space, residential space, and park space, has a really unique form—it curves outward on the front and back like a lens with an angled curve on the top (Figure 2). It’s pretty cool, especially when the building is 38 stories and 177 meters tall. This massive landmark began construction in January 2009 and opened in January 2015, being one of the newest additions to London’s skyscrapers. The Walkie Talkie is part of the booming skyscraper trend in the City of London (not “city of London,” but the confusing name for the smaller jurisdiction within the city), in the financial hub of the city. Even though it laser-beams cars (we’ll get to that later), this structure is a great addition to the skyline.

Historical Significance

This specific shape was unprecedented in skyscrapers when it was designed, and the shape is so unique that it has earned both praise and harsh criticism. With such a new building, the impact of the structure cannot be measured yet, but my guess is that it will inspire many architects and engineers to think outside the box in terms of form. I also think that the criticism earned by the building will motivate these designers be a little more conservative in design, still displaying new forms, but in a less exaggerated way. Outside of form and more on the engineering side, the unique cantilever approach (see structural analysis) used was basically custom-made for this building. Setting the core off center and cantilevering part of the curved façade in suck a specific way was extremely innovative, and we will have to wait and see if this technique gets adopted in other skyscraper designs.

Cultural Significance

The building’s culture impact is mainly through its divisiveness. The reception for the building has been very mixed. Many admire its innovative design and unique visual style, but the building is also hated by many for some pretty hilarious reasons. Besides some not enjoying the aesthetics of the skyscraper, many Brits are mad because it melts cars and causes wind tunnels, sometimes adding that it functions like “Bond villain tower.” If a building blew wind in my face and melted my car with a solar beam I wouldn’t like it either. The Walkie Talkie also affects the culture of the city through its environmental style. Along with various awards due to sustainable design, the building’s three-level park is an important fixture of the city. Although the park’s lack of complete public access is another point of criticism directed at the Walkie Talkie, this feature is still a positive.

Structural Art

In term of efficiency, this building’s structure carries complex loads extremely well. The architectural planning can be blamed for the poor performance in some areas (melting cars, channeling wind), but there have been no significant structural issues. Though the building is very new, and still must face years of trial, the efficiency required out of the structure

The whole point of this building is that it goes against what physics demands out of skyscraper form, and the result is poor economy. A tower of the same height could have been built with far less materials, so there is high cost is due to this over-the top design. Although this problem is due to the architectural design, it is impossible to say that this skyscraper minimizes cost for its particular function.

In the ideal of elegance, the Walkie Talkie building is difficult to measure. It succeeds in looking awesome, but using Billington’s concept of structural elegance shows that it does not succeed in this area. The visual aspects of the building were guided by architectural ideas, with the engineering just being done to ensure safety, and the load path is not on display.

Structural Analysis

One of the most challenging aspects of designing this skyscraper was that its architecture demands that its design is the opposite of a typical column. Columns carry gravity loads to the grounds, so a tapered shape toward the top is optimal, while increasing width toward the top is not preferred. The solution the team used was to set the concrete core of the building off center, since the building is heavier on one side, and also use perimeter columns of steel plate box sections. The loads travel downward through four main paths: the two outer columns of the inner core, and the two steel columns near the perimeter (Figure 3).

Figure 3 – Load Path

The distance from the core to the edge of the building range from 11 meters to 22 meters, and the solution was to have a max 18-meter span from core to perimeter column. Any beam distance above 18 meters is cantilevered. To get an idea of the forces present in these cantilevered, I calculated the forces in the beam with the longest cantilever, assuming simple supports (Figure 4). I named the weight per meter of steel beam w, the load transferred to the inner core column L1, and the load transferred to the outer column L2. Since max cantilever occurs just below the top floor, these loads are due to the slab and roof above.

Figure 4 – Cantilever Calculations

The calculations show that By is always supplying a positive force, but Ay only supplies a positive force if L1 > 52.6w. As the cantilever length decreases going down the building, L1 increases while w decreases, showing that the support in the inner core column increases significantly moving toward the base of the tower, due to both the weight above and the cantilever length.

The geometric changes at each floor demanded advanced technology to communicate the design and construction of the building to those outside of the design team. To tackle these challenges, advanced 4D-BIM modelling—3D building information modelling with time added as a fourth dimension—was used, allowing the team to anticipate challenges and maximize safety. This information was mainly used to communicate the building’s program with the clients and mitigate communication issues with the construction team.

Personal Response

The Walkie Talkie Building was only ever slightly impressive to me until I got up close. The first time I visited London I didn’t really give it a second thought. I thought it was a slightly cool building that was probably very difficult to build. When I stood under the amazing vertical curvature of the building, though, I was blown away. It was pouring rain, but standing in front of the building kept us out of the rain. Looking up, it looked as if though the building should be falling on top of me, and the curvature makes the building appear even taller than it really is. As a bonus, I also learned that the top of the building has a full park, which I would love to check out. Overall, I think this is one of the most visually impressive structures in the world with some very impressive engineering that allows a really unique form. 


[1] https://www.steelconstruction.org/design-awards/2014/commendation/20-fenchurch-street-london/

[2] https://www.telegraph.co.uk/business/2017/07/27/walkie-talkie-building-sold-hong-kong-company-record-128bn-deal/

[3] https://www.steelconstruction.info/20_Fenchurch_Street,_London

British Airways i360 (The London Eye’s Little Sister)

I went down to Brighton for the day to hang out with one of my friends from there. She toured me around and, of course, we ended up on the beach. She pointed out to me, in the distance, a huge column and told me it was their brand new observation tower. She also said it was pretty controversial because it was built with taxpayers dollars, so I thought it would be interesting to do more research into.

Structure Information

Figure 1: My View of the i360 on Brighton Beach

This observation deck on Brighton Beach is called the British Airways i360. The BAi360, as British Airways calls it, cost £46 million to design and build. It was funded by Brighton and Hove City Council, Coast to Capital Local Enterprise Partnership, and Brighton i360 Ltd. Brighton and Hove City Council was loaned the money from the Public Works Loan Board and Bright and Hove City Council receives a potion of the profits. The observation deck opened in the summer of 2016 and has already begun to promote other development along the shoreline in Brighton. [1]

The BAi360 can be used as an event space as well as for the typical 25 minute “flights” to the top. 175 people can ride in the pod at the same time! The BAi360 website boasts that the structure itself is 20 feet taller than the London Eye, which is considered the BAi360’s “sibling.” [1]

Speaking of the London Eye, the architect for the London Eye, Marks Barfield Architects, was also the architect for the British Airways i360. The structural engineer on the project was Jacobs. [2]

Historical Significance

Figure 2: i360 Construction [2]

The British Airways i360 has won many awards, but the most notable awards are being the world’s tallest moving observation tower in 2017 and holding the Guinness Record for the world’s most slender tower. The construction process was the first of its kind, without cranes for the height addition and from the top to the bottom, which I’ll discuss further in the structural analysis. This construction method meant that construction workers were only needed on the ground, which is must safer than being 162 meters in the air. Figure 2 shows how much shorter the crane used in construction was compared to the completed tower. The liquid dampers used were also revolutionary in the UK. [3]


Cultural Significance

Figure 3: The i360 at Night [2]

The i360 seems pretty out of place in Brighton next to the Brighton Pier with arcade games and festival food, and it seems some locals agree. The i360 gained many nicknames, typical of the British, one being the iSore, another the Brighton Pole, and many others which are very inappropriate [4]. Figure 3 shows how tall the i360 is compared to the rest of the shoreline.

The investment process was also extremely controversial because the construction was just getting started as the recession hit and suddenly there wasn’t money for the structure. Up until then, it was to be only privately funded. In 2012, Brighton and Hove Council pledged enough money to get the project restarted, and in 2014, it pledged even more money when more funding walked out the door and the architects could only put up so much to keep it going. [5] In an effort to subdue these criticisms, local residents receive half-price tickets and each public school students in Brighton and Hove got a free tickets the summer the i360 opened [1].

With revenue being what was expected and the new development starting in the area, it seems that the i360 is helping the economy in Brighton and promoting even more tourism. It also seems to commemorate the old West Pier that was falling apart and eventually burned down (the arsonists were never caught), which metal skeleton just sits in the sea now in front of the i360.

Structural Art

Despite the public backlash and perhaps its out-of-placeness, I do think that the BAi360 is structural art.

The efficiency is obvious – with the recession, the architects and engineers were under huge economic constraints. On top of that, being the most slender tower in the world means the i360 really doesn’t use much material. My friend from Brighton told me that most of the area is in the Green Party, Brighton runs some buses off of recycled oil from making fish and chips, and there is a wind farm in the sea for energy, the i360 even reuses its energy from descending to go up the next time; all of which indicates that being efficient is extremely important to the area.

As far as economy, the construction method was absolutely considered in the design. From the architects that came up with lifting the London Eye from the River Themes in under a week, the i360 was built using jacks and keeping construction workers on the ground because of the huge wind loads at the top of the i360.

Elegance may be harder to see because of the location of the i360, but it is clear that this structure’s load goes straight into the ground, since it is just a column. There is nothing extra to hold up the column and the simplicity truly makes the i360 structural art.

Structural Analysis

As mentioned earlier, the i360 was thought up by the designers of the London Eye and had a novel construction method. The tower itself is made of steel, covered with perforated aluminum to prevent wind vortices. Inside the tower are 78 jugs of Australian water to further resist wind loads. The construction was done by transporting pre-made materials on a barge to the beach. A jacking frame was put up and 17 50-100 ton “cans” were jacked up, like you’d jack up your car to change a tire, but much larger. [3]

Due to the wind, there is a little more complexity to the i360 tower than once first thinks. The columns is the first structural component I first thought of, the second being the observation pod. After doing research, the liquid damping system is the final structural component to consider. The liquid dampers were “tuned” to the three most common natural frequencies of an undamped tower [7].

Figure 4: i360 Load Path

The tower is 162 meters high and 3.9 meters in diameter, 4.5 meters including the covering [3]. The viewing pod carries 200 passengers and goes up to 138 meters [3]. The pod is 18 meters in diameter and weighs 94 tons [8]. The tower only closes once wind gusts are up to 44 mph, which is 243 N/m2 for this structure according to a velocity-pressure chart [5]. The foundation is 6.5 meters deep to hit chalk rock, and because of tides, the base had to be able to sit in water. The foundation is 4,150 tons while the tower is 1,200 tons. 200 people can weigh about 18-20 tons, and they need to be able to stand all on one side of the pod in case something interesting is happening for them to all look at. The code in Britain for wind loading is to withstand “the worst three second gust in the middle of the worst storm which occurs on average every 50 years.” Apparently, this translates to the structure being able to deflect over a meter safely. There were redundant measures put in the tower for dynamic loading, such as random outstands to “confuse the wind,” as Dr. Stewart would say. [6]

The load path for the i360 is very simple: the mass from the pod goes to the tower and then from the tower the load goes to the foundation. The load path can be seen in Figure 4.

Since the pod will only operate at conditions under 44 mph gusts, I chose to analyze the worst-cast scenario with 44 mph winds. This includes all of the people being at one point on the edge of the pod and 44 mph winds creating pressure along the entire structure. With these assumptions, I calculated maximum moment and maximum shear, which are at the base of the tower since the tower can be treated as a cantilever, as well as the reaction forces of the foundation on the tower. The calculations and diagrams I used are shown below. 

The idea of the the i360 came from the architects, not the city, which is somewhat unusual. The i360 was modeled in a computer, and views of the structure with the town of Brighton behind it were presented, as well as views of what the inside of the pods would look like during flight. Figure 5 shows the i360 from a beach-view while Figure 6 shows the inside of the observation pod. These models were shown to Brighton and Hove Council and members of the community.

Figure 5: i360 Model [9]

Figure 6: Inside Observation Pod Model [10]

Personal Response

I’m so glad I decided to look further into the British Airways i360 after visiting Brighton. The story behind the structure and how innovative it is was really interesting. By seeing the i360 in person, I was able to see just how much it contrasted the rest of the town and see all of the new development happening in Brighton just nearby the i360. Since the i360 has dampers, wind loading, and live loading, I feel like everything I have learned this summer really came together for me to learn about the BAi360 in this final blog post.


1 http://britishairwaysi360.com/about/faqs/

2 http://www.marksbarfield.com/projects/brighton-i360/

3 https://www.istructe.org/structuralawards/2017-winners/tall-or-slender-structures/2017/british-airways-i360-at-brighton

4 https://www.theguardian.com/artanddesign/2016/aug/02/brighton-i360-review-marks-barfield-british-airways

5 https://www.theguardian.com/uk-news/2015/aug/28/its-a-bonkers-outsized-flagpole-brighton-greets-the-worlds-tallest-moving-observation-tower

6 http://britishairwaysi360.com/latest-news/the-science-behind-the-i360-tower/

7 https://www.newcivilengineer.com/technical-excellence/super-tall-super-smart-the-brighton-i360/10010065.article

8 http://britishairwaysi360.com/wp-content/uploads/2015/05/i360-Media-Pack-Updated100717-1.pdf


10 http://www.c-mw.net/brighton-i360-seeks-global-stage/

Le Pont des Arts

Structure Information

The Pont des Arts is an iconic bridge spanning across the Seine River in Paris, France. Construction of the current bridge began in 1981 and finished in 1984. Figure 1 below is a photo of the bridge today.

Figure 1: Le Pont des Arts, Paris, France

In english, “Le Pont des Arts” translates to “The Bridge of the Arts.” The name of this bridge is very fitting for its function because it serves as a pedestrian bridge that links the Institut de France and the central square of the Palais du Louvre. The Institut de France is a French learned society that houses French Academies such as the Academies of Music, Humanities, and Sciences. The Palais du Louvre is a former royal palace which is now the largest art museum in the world. Figure 2 below shows the bridge name carved in to the abutment closest to the Institut de France.

Figure 2: Bridge name carved in to the stone of one abutment

The Pont des Arts was designed by Architect Louis Arretche, and the structural engineering was done by Enterprise Morillon Corvol Courbot (EMCC) [1]. The bridge was built as a replacement for the former bridge built under Napolean Bonaparte. This bridge is a structure paid for by French Public Works.

Historical Significance

As previously stated, the Pont des Arts was built as a replacement for a bridge that was built in the same place across the Seine in 1804. The current bridge is almost identical in design to the original bridge, so by modern standards, the current bridge cannot be considered an innovative structural engineering design. However, the original bridge, completed in 1804 was the first metal bridge to be constructed in Paris, 19 years after the building of Iron Bridge in England. Napolean Bonaparte asked engineers to design a bridge that resembled a garden that was suspended over the Seine [2]. The original bridge was elegant, lightweight and constructed from cast iron, placing it on the cutting edge of engineering in its day. The piers of the original bridge were constructed in masonry as were all the piers of bridges along the Seine, but the use of cast iron was a very new construction technique. The construction of the present bridge did not involve any new construction techniques.

The current Pont des Arts is a steel arch bridge. Its historical connection and consequently almost identical design to the original bridge in the same location makes it unimpressive structurally by modern standards. The best existing example of a steel arch bridge is the Syndey Harbour Bridge in Sydney, Australia. It is the largest steel arch bridge in the world. Figure 3 below shows an image of the Sydney Harbour Bridge.

Figure 3: Sydney Harbour Bridge

Cultural Significance

The current Pont des Arts bridge is internationally known and is one of the most famous bridges in Paris. It is first iconic because of its location–the link between two of Paris’ most iconic buildings. The Palais du Louvre on the bridges right end has housed French kings since its construction in the 1200’s, and is now the largest and arguably most famous art museum in the world. On the left end of the bridge, the Institut de France houses the agency that manages over 1000 foundations, museums and chateaux that are open to the public, making it a major cultural landmark.

In addition to its locale, the Pont des Arts is a cultural landmark because of its connection to history. The bridge that was originally in its place was ordered to be built at the beginning of the rule of Napolean Bonaparte. Napolean’s empire dominated the French Revolutionary wars and facilitated the development of Paris with structures such as the Arc de Triomphe and the Pont des Arts.

The original concept for a metal bridge in Paris in the beginning of the 19th century was largely rejected by famous Parisian architects of the day. These experts thought that it would lack monument because of its lightness and metal form. The aesthetic of metal was vastly different from the monumental stone bridges between which the Pont des Arts was to be built. However, when construction was completed, the Parisians “took the bridge to heart” [3]. As with most bridges of the time, the Pont des Arts was a toll bridge which cost one cent to cross. On the day the bridge was opened, 65,000 Parisians paid their penny to cross the new bridge [3]. The permanence of the original design that continues in the Pont des Arts today describes the iconic and loved nature of this bridge.

There is no record of injured workers in the construction of the original Pont des Arts built in 1804 or the new Pont des Arts built in 1984. However, the original Pont des Arts was demolished in 1980 because of structural weakening and damage from barges. There were barge collisions throughout the life of the original bridge, considered to be the human cost of the bridge.

Today the Pont des Arts is an internationally known landmark. The bridge is a favorite for artists, musicians and people in love. In 2008, a tradition began which gave the Pont des Arts the unofficial name of the “Love Lock Bridge.” Couples would write their initials on a lock, attach it to the side rails of the bridge and throw the key in to the Seine River as a symbol of eternal love. The tradition became so popular that there was an additional 45 tons of weight added to the bridge from the locks [4]. This loading caused structural weakening and eventual collapse of one railing section. In 2014 the railing sections were removed and replaced with plexiglass sheets. Figure 4 below shows a railing section with the love locks in tact.

Figure 4: Pont des Arts railing with love locks attached [4]

The Pont des Arts is still used as a pedestrian bridge and remains an iconic part of Paris.

Structural Art

The design of the current Pont des Arts was dictated by the original iron design in 1804. The structure has been described as “light” since its original construction, which has been considered a good and a bad thing depending on the critic. I think that the original design boldly rejected the heavy monument of stone that was the norm for Parisian bridges at the time. The structure was able to be made light because of the new material of iron. In this sense, form was dictated by function. I think this is a major requirment of structural art, and the Pont des Arts embodies this requirement. David Billington states that aesthetics should be the final judgement when deciding if something is structural art. I was immediately drawn to this bridge. It stood out to me while strolling along the Seine because of its elegance and lightness when compared to the countless bridges of heavy stone that span the Seine. I think that the only thing that subtracts from the status of the Pont des Arts as structural art is the fact that the modern bridge was designed by an architect and not an engineer. Similar to this, the piers of the modern bridge are made of reinforced concrete, but faced in stone to pay tribute to the design of the original bridge. Hiding the true material that takes load is a way that the structure does not demonstrate structural art.

Structural Analysis

The modern Pont des Arts is designed to replicate the original bridge that was built in 1804 and demolished in 1980. The original bridge was a cast iron arch bridge with nine iron arches spanning a total of 509 feet. The form of the bridge was modeled after the British metal arch bridges that preceded it. The supporting bridge piers were constructed of stone masonry using cofferdam systems to block the water around the pier and pump it dry with buckets. The deck was contructed using wooden planks.

The design of the modern Pont des Arts bridge is almost identical to that of the original bridge. The differences lie mostly in construction materials used. The current Pont des Arts superstructure is constructed in steel. Steel is lighter, stronger and more ductile than iron, making it the clear modern choice after the failure of the original iron bridge. The piers are constructed in reinforced concrete but faced with masonry to pay tribute to the original bridge. The deck is constructed in timber, another tribute to the original bridge design. Another departure of the modern bridge from the original bridge design is the number of arches. The current bridge has seven arches instead of nine, a design choice that was made to be consistent with the number of arches of the adjacent Pont du Neuf, and made possible because of the ability to make longer arch spans with modern construction materials and technology.

The structural system employed in this bridge is repeating three-hinged arches. There are seven arches from bank to bank and there are five repeating arch systems that span from edge of deck to edge of deck as shown in Figure 5 below.

Figure 5: Five arches which span from edge of deck to edge of deck meeting at one pier

Figure 6 below shows an elevation view of contiguous repeated arches meeting at one pier.

Figure 6: Arches meeting at one pier

The repeated arches are supported by reinforced concrete piers and abutments on either end of the bridge.

Load from pedestrian traffic and the timber deck is transmitted from the deck to the spandrels connecting the arches to the deck. The load moves through the spandrels to the arches. The arches are in compression. Since the structural system consists of repeated arches, the horizontal thrust generated by each arch at the arch connection to the pier is cancelled out by the horizontal thrust generated in the opposite direction from the contiguous arch. The vertical load at eah arch end is transmitted through the bridge pier to the ground. The only horizontal thrust that is realized is at each end of the bridge and is taken by the abutments. The load path is shown in Figure 7 below.

Figure 7: Load path of one repeated arch

Using this load path and assumptions about the dimensions of the bridge, one of the total 35 arches can be analyzed. The dead load of this bridge is calculated using the density of the timber decking which is assumed to be 41.8 pcf [6]. Assuming the deck is 1 ft thick, the area dead load is equal to 41.8 lb/ft^2.

European building codes specify that the live loading associated with pedestrian footbridges is typically 5 kN/m^2 [5] which is equal to 104.4 lb/ft^2. The deck has 7 spans totaling 155 m or 508.5 ft and a deck width of 10 m or 32.8 ft. By the principle of superposition, to get total linear loading, the dead and live area loads are added and multiplied by deck width as shown below.

(41.8+104.4) lb/ft^2*(32.8 ft)= 4795.4 lb/ft

The length of one arch span can be found by dividing total span by number of arches as shown below.

(508.5 ft)/(7 arches) = 72.6 ft/arch

Height of arch is assumed to be 24.2 ft based on the visual proportion to arch length.

From these data and assumptions, and assuming the the load will be transferred completely to the arch by the spandrels, the following model shown in Figure 8 can be used to perform the analysis of one arch.

Figure 8: Simplified model of one arch

To analyze find the reaction forces the arch will be cut at the center hinge. A model of the left side of the cut is shown below in Figure 9.

Figure 9: Left side of arch cut at center hinge

By symmetry using the global structure, reaction force By is equal to zero. Ay can be found using sum of forces in the y-direction as shown below.

Ay – (4795.4 lb/ft)*(36.3 ft) = 0

Ay=174073.0 lb

Using the sum of moments about the top hinge, reaction force Ax can be found as shown below.

Ay(36.3 ft) – Ax(24.2 ft)-((4795.4 lb/ft)(36.3 ft)(1/2)(36.3 ft))=0

Ax = 130552.6 lb

From these equations we know that 174.1 kips of force is being transmitted vertically from one end of the arch to the pier and 130.6 kips of horizontal thrust is generated, which is counteracted by the contiguous arch. Since there are 5 pin connections at each pier with two arches connected at each pin, the total vertical force exerted on the pier can be calculated using the following equation.

(174073.0 lbs)*(5 pins)*(2 arches) = 1740730 lbs

We can use this force and assumptions about the geometry of the cross section of the piers to calculate compressive stress in each pier. It is assumed that the piers are rectangular in cross section, 32.8 ft in length, and 2 feet in width. The area of the pier can be calculated using the following equation.

Area = (32.8 ft)*(2 feet) = 65.6 ft^2

Assuming the cross-section is constant, the stress in the pier is found using the following equation.

Stress in pier = (1740730 lbs/ 65.6 ft^2)*(1 ft^2/144 in^2)= 184.3 psi

This value can be compared to typical strength of reinforced concrete, equal to 4000 psi.

4000 psi >> 184.3 psi

Based on these calculations, the piers are designed with a safety factor of 21. This is very high for a bridge, and should be considered higher than actual design because of assumptions made.

Sum of forces in the x-direction can be performed to find the horizontal reaction force Bx as shown below.

Ax – Bx = 0

Bx=130552.6 lbs (in the negative x-direction)

It is assumed that Bx represents the compressive force in the arch. We can use this force and assumptions about the geometry of the arch cross-section to find compressive stress in the arches. It is assumed that the cross-section of the steel arches are rectangular and the area of the cross-section is equal to 10 in^2.

Stress in arch = 130552.6 lb/10 in^2 = 13055.3 psi

Steel has a compressive strength of about 25000 psi. Comparing the design stress to material properties of steel,

25000 psi > 13055.3 psi

This indicates that the steel superstructure is designed with a safety factor of about 1.9. This value is close to what would be used in the design of a bridge.

It is assumed that since this bridge was built as a structure of French public works, drawings or plans were made to the specifications of French bridge building codes and communicated to the the owner (French government).

Personal Reaction

I saw this bridge while strolling along the Seine River from Notre Dame Cathedral to The Eiffel Tower. As I previously stated, I was immediately drawn to this bridge because of its lightness compared to the heavily ornamented stone bridges around it. Standing on the bridge with two huge French monuments on either side of me, it was amazing to me how much history and culture could be built in to a structure as simple as a foot bridge.



[1] https://structurae.net/structures/pont-des-arts-1984

[2] https://www.cometoparis.com/paris-guide/paris-monuments/pont-des-arts-s959

[3] https://www.napoleon.org/en/magazine/places/pont-des-arts-bridge/

[4] https://www.citymetric.com/horizons/paris-has-replaced-padlocks-pont-des-arts-padlock-themed-graffiti-1113

[5] http://www.cbdg.org.uk/tech2.asp

[6] https://www.forza-doors.com/performance-guides/general-guidance/timber-density-chart.aspx

Grande Arche de la Défense (Great Arch of Defense)

Structure Information

            Wow, A huge rectangle and a cloud. That was my initial reaction when I first seen the structure.The Grande Arche de la Défense (Great Arch of Defense) not a rectangle is a huge arch located in La Défense, Paris business district. The view from the top of the steps are breath taking. The arch was built to mark the end of the Triumphal Way, the east-west axis that connects the Louvre with La Défense. The purpose of the building today is used for office space. This building was a part of a design competition in 1982, by the president François Mitterrand to commence new construction activity [2]. Architect Johann Otto von Spreckelsen and engineer Erik Reitzel designed the winning entry. They won because their design had stability, simplicity and purity of form [2]. This was cool, because a lot of the designers we talk about in class were involved in design competitions. The designers wanted this to be a place where diverse people could meet and converse. Construction started in 1985, and the building was complete 1989. This project was funded by the government through with a budget of 1.3 billion francs.


Figure 1:The Grande Arche de la Défense at Night

Figure 2:The Grande Arche de la Défense Currently

Figure 3:The view under the “Cloud”

Figure 4:The View from the Stairs

 Historical Significance 

            Based on other Paris monuments the arch is twice the size of the Arc de Triomphe and its archway is large enough to fit the Notre-Dame Cathedral. The arch is made of pre-stressed concrete. The cloud spans between the inside of the archway is a tent-like structure. It was created to reduce wind resistance and it also achieves the effect of seemingly reducing the gigantic proportions of the arch [2]. The cloud is made of white plastic panels that are suspended by steel cables to the sides of the arch [2]. Before the designer built the arch the designed three churches. It was stated that he relied heavily on simple geometrical figures, hence the hollow cube (The Grande Arche de la Défense) [3]. The pre-stressed construction tools were also used for the churches, so this material was not new to him. This was his first time building at this scale, so he wanted to make sure it was a cultural icon for the upcoming centuries.

Figure 5:Size of Paris Monuments


Cultural Significance 

The 158,000 sq. meters of space is used as a communications center for the La Defense District. It also has digital presentation auditoriums and office space for private parties [3]. The citizens loved the arch, because it was built to mark the end of the Voie de Triomphe (Triumph Way), a large road that connects the east and west of the city. In Paris, they have a thing, where monument mark the end of territories. When I searched for historical events, it was so funny to me that a person getting stuck in a toilet was historical. Margret Thatcher aka Iron Lady aka UK prime minister at the time, got stuck in the toilet. She was visiting the top rooftop, but had to go to the toilet. When she was trying to get out the handle broke, so her body guard had to bust the door open [4]. That was the start of the downfall of the arch.

In 2010-2014, the roof with its viewing platform, gastronomic restaurant, computer museum and conference center, which attracted around 250,000 people a year was closed to the public because of safety concerns. The area around the foot of the north side of the arch has been sealed off after fears of crumbling marble falling on people below, and staff of the French ecology and housing ministries, who occupy the south side, have complained of gloomy corridors and offices with oppressively low ceilings and no natural light [4]. The government gave €200 million to renovate the south side of the arch. Since the government did not give money to fix the north side, out of 30,000 sq. m of offices, 24,000 sq. m are empty and rents have fallen [4]. When I visited, there was renovations going on throughout the entire arch. It


Figure 6:The Grande Arche de la Défense during a busy Day


Figure 7:The Grande Arche de la Défense Under Construction

Figure 8:The Grande Arche de la Défense Construction Information


Structural Art

David Billington stated that structural art can be defined using three E’ principles: efficiency, economy, and elegance. The pre-stressed concrete is used in a wide range of building and civil structures where its improved performance can allow longer spans, reduced structural thicknesses, and material savings compared to simple reinforced concrete [2]. I was efficient to use his material for a structure of this magnitude. Economically the arch is doing okay. It cost 1.3 billion to build the structure, and a big renovation of 200 million. I am sure there are more renovation cost from what I seen. It makes money from tours and rent, so I am sure the cost balances out. It is a simple cubic structure that can be seen easily, so it has much elegance except when it is under construction. Based on those allegations it is structural art.


Structural Analysis

            The building is main component is pre-stressed concrete. It is based on a 21-meter grid, where it is mirrored on the top and bottom with four pre-stressed concrete transversal rigid frames of columns attached to main beams of roof and base components [3]. Four additional secondary pre-stressed cross beams in the roof and base are used to stabilize these rigid frames [3]. The roof beams are 70 m long, 9.5 m tall, and weigh 2000 tons each. Four gabled walls were created at 45 degrees, holding 6 horizontal mega-structures on either side. A seven-floor modular was utilized to create a substructure, repeating the modular five times and built simultaneously with the superstructure. For the base, there are twelve foundation piles resting on a limestone shelf 14 meters below ground level. The piles are 8 meters in wide at the base, and the piles flared to 15 meters to meet the structure’s base [3]. The cube’s dimensions are 117 m wide, 112 m deep and 111 m tall [3].


Figure 9:The Grande Arche de la Défense Load Path


The self- weight of the main beams is given and they are 19.99 m/ton. The self- weight of the secondary beams are considered point load and they are given at 22.04 m/ ton.. The length is 106.90 m, I will calculate the reactions and moments.

Figure 10:The bottom beams analyzed

Figure 11:The Reactions and Moments Calculations

These 3d drawings bellow, shows the structural composition of each component. Allowing the engineer to understand the drawings.

Figure 12:Base Beams

Figure 13:Shear Columns added

Figure 14:Roof Beams Added

Figure 15:Diagonal Shear Walls Added

Figure 16:Bracing Added

Figure 17:Perpendicular Beams Added

Figure 18:Final Overview

 Personal Response

I did not realize how big the cube like structure was. Being able to see the Notre Dame in person and seeing that the it could fit into the arch was amazing. From the pictures, I seen online, I did not know the entrance was steps. The steps blend in so well with the arch.

Figure 19:Me at The Grande Arche de la Défense


[1] http://www.aviewoncities.com/paris/archedeladefense.htm

[2] https://www2.deloitte.com/content/dam/Deloitte/cz/Documents/real-estate/Iconic_Buildings_La_Grande_Arche_Smart_16winter.pdf

[3] http://faculty.arch.tamu.edu/media/cms_page_media/4433/grandearche.pdf

[4] https://www.thelocal.fr/20140805/paris-the-not-so-grande-arche

[5] http://famouswonders.com/grande-arche-de-la-defense/

L’Arc de Triomphe de L’Etoile

  1. Structure Information 

The Arc de Triomphe de L’Etoile was commissioned in 1806  by the French emperor Napoleon to commemorate the Grande Armee, the French army at the time. He wanted it to symbolize victory and the invincibility of the French army. He wanted his soldiers to walk victoriously through the arc on their way back to Paris. Construction began on Napoleon’s birthday on August 15the 1806 and ended in 1836, and it officially opened on  July 29th(1).

Résultat de recherche d'images pour "arc de triomphe"

Figure 1: Arc de Triomphe de l’Etoile [3]

It is located in Paris at the end of the Champs Elysees, at Place Charles de Gaulle,  and is encircled by a huge traffic circle called l’etoile, meaning the star. This is where it gets its name from. It was designed by the French architect Jean Francois Therese Chalgrin (2) but he died in 1811.  Jean Nicholas Huyot continued the job of architect after his death (5). At the time of its completion, it cost 9.3 million francs(5). This was paid for by the autonomous amortization fund. Funds were disbursed from the “Grande Armee” at the beginning of each month for the erection of the monument.


  1. Historical Significance 

The design of the arc is based on the Roman Forum and is an example of Neoclassical architecture(1). The design was modernized by adding archways on each side and hollowing out the pillars to allow people to climb to the top (2). There is nothing structurally innovative in the design and did not employ any particular construction technique.  The inspiration for this arch was the  Arch of Titus, constructed in Rome is 81 AD. It is the best existing example of a victory arch. Arch of Titus. All the other victory arches have been inspired by the arch of Titus. The arch of Triomphe popularized the designed and brought it to the public eye. The arch of General Staff Building in Russia was built to mock the French and commemorate their defeat over Napoleon and took its inspiration from this arch.

Figure 2: Arch of Titus [6]


  1. Cultural Significance (10% of grade)

The Arc of Triumph is one of the most historical monuments in France. It has been the site of many historic moments. The arch was highly anticipated. At the time of its commissioning, France had gone through a series of major victories with Napoleon. The arch is one of three monuments commissioned by Napoleon to celebrate the French victories after his spectacular win at Austerlitz in 1805 (11). The other two are the Arc de Triomphe du Carrousel, the Vendôme Column. It was to be a symbol of their supremacy and invincibility to the world.  Its large scale and intricate designs were to be used to boast about their military strength and celebrate their winning strike. Fortunately, no one died during the construction of the arch. After Napoleon lost to the Russians and abdicated in 1814, work on the arch stopped. It wasn’t until 1830 that the citizen king Louis Phillipe, wanting to honor the revolution, ordered the arch to be completed.


Image result for arc de triomphe du carrousel near the louvre museum in paris

Figure 3: Arc de Triomphe du Carrousel


Image result for vendome column

Figure 4: Column Vendome


Today its used to honor those fallen for France. It is used to commemorate the French soldiers that died during world war one. In fact, buried underneath it is the tomb of the unknown soldier who died during the war. He was buried there on November 10th 1920 and on top of the tomb lies the inscription: “Here lies a French soldier who died for his fatherland 1914-1918” (10).  Since 1923, an eternal flame burns at the center of the tomb. Each night at 6:30pm the flame is rekindled, this too in memory of fallen soldiers.


Image result for eternal flame arc de triomphe

Figure 5: Fallen soldier tomb with inscription and eternal flame

At its location,  Charles de Gaulle survived an assassination attempt and so did President of the time Jacques Chirac in 2002 (10).


  1. Structural Art 

In order to access if this is structural art, I will be looking at the E’s: economy, efficiency, and elegance.

First, let us take a look at the economy. The arch cost 9.3million french franc, which equals to 76.6 million dollars in 2015 (7). This is a lot of money, even back then the cost of the arch was seen to be astronomical. This is because the arch was not designed with economy in mind. It uses stone from Beaune in burgundy South of France (8) instead of cheaper materials like concrete.

Second, let us look at efficiency. First of all, there was no real need for this arch, it is purely decorative and commemorative.  Besides that, it has no other purpose. The arch itself is very thick, with large legs and is very heavy in decorations. Here again,  the arch was not designed to be efficient but to be beautiful and meaningful. It is important to note that it is hollowed out in the center, allowmg to save material.

Third, let us look at elegance. The arch is beautiful. It has intricate designs all around. I highly doubt that Billington would consider it elegant though. It does not really blend well with its surroundings and sticks out like a sore thumb. It is situated in the center on one of Paris’s largest roundabouts and its different architectural style, as well as massive size and thickness, does not allow it to merge with the distinct look of the city around it. In my opinion, the contrast between its surroundings and the arch adds to its beauty but does not do much for elegance.

This arch is in no way an example of structural art as it does not satisfy any of the three E’s.

Image result for arc de triomphe arch top view

Figure 6: Arch of Triumph sticking out [9]


  1. Structural Analysis (50% of grade)

The arch of triumph is a triumphal arch, meaning it is an archway structure characterized by one or more arched passages with large piers on its sides and a flat entablature and commemorative decorations or inscriptions. The Arch of Triumph has two vaults going through it: a large one and a smaller one. The piers are hollowed out to allow people to climb stairs to the top where there is an attic.

The initial design which was done in collaboration with a man named Jean Arnaud Raymond continued columns which was then discarded (as was Raymond). Columns would have had no structural purpose anyway. Foundations were started in 1806 (7) and took two years to be completed. Then they worked on the four piers. In 1811 when the main architect died, the piers were only 33ft above ground. By 1812, they rose all the way to the vaults but construction stopped due to the abdication of Napoleon Bonaparte.  Construction resumed in 1832 and finally ended in 1836.

The structure is made of stone from Burgundy, France: limestone, and cobblestone. It is 164ft high and 148ft wide and 72ft deep with a foundation 27.5ft deep(2). Its large vault is 95.8ft high and 48ft wide. The smaller vault is 61.3ft high and 27.7ft wide. The entablature is supported by the four massive piers. The thickness of the piers allows to diminish the thrust forces from the arch. A similar principle to corbelling is applied here in a way. The thick walls on either side of the arch allow it to remain stable against all loading, preventing collapse.

For this structure, there are live loads associated with people visiting and climbing the structure.  The other loads we are dealing with are self-weight, and environmental loads such as snow and rain. The load travels from the crown to the arches then the arches distribute the forces to the piers and the piers to the ground. This is shown in figure 4 below. The crown is in tension, the piers and the arch are in compression.


Figure 7: Load Paths


I order to analyze this structure I will solely use self-weight and determine if it is safe to have people on the structure as they have been allowing tourists to the top these past years. The monument weighs 50 000 tons, and 100 000tons if you include the foundations. From this information, we can infer the tributary areas’ weight, calculate the load on each pier as well as the maximum force on the arches.




The maximum force on the arches is as shown. In case of a load larger than calculate the arches might fail under the weight. Now I will calculate the actual force on the and the maximum force on the piers in order to prevent buckling.

Based on these results we can conclude that it is safe to allow tourists to climb the structure as the load on the piers is very small compared to the critical buckling load.


The main stakeholder for this arch was Napoleon Bonaparte as he had ordered the construction of the arch by imperial decree. He wanted victorious soldiers to walk underneath the arch on their way home. Even though it was completed long after his death, he got the opportunity to live that experience in a way. A wooden model was erected for him and his new wife to cross after their wedding(1). This allowed him to see what the arc would look like once it was finished and to actually interact with the design since it was life-sized.

  1. Personal Response   

The arch is a lot larger in real life than I had realized. It is incredibly big, very large and high. Standing next to it made me feel like an ant or a shrunken person. It is definitely an imposing piece of architecture. Before visiting it I had assumed the car passed underneath the arch but they actually do not It is situated in the center of the roundabout and every car that passes by has a great view of the structure.

After visiting the structure I better understand how important of a role it plays in France’s history. You can not see it easily on pictures but the whole arch is decorated with very beautiful sculptures and inscriptions all around. It gives it a more solemn air and tugged a little at my heartstrings. It is a beautiful piece of culture with a beautiful message.



[1] https://www.britannica.com/topic/Arc-de-Triomphe

[2] http://www.arcdetriompheparis.com/

[3] https://www.ceetiz.fr/paris/arc-triomphe-e-billet-valable-toute-annee

[4] https://www.slideshare.net/KathrynReuter/a-brief-analysis-of-the-arc-de-triomphe-and-the-gateway-arch

[5] http://www.softschools.com/facts/europe/arc_de_triomphe_facts/2193/

[6] https://www.timesofisrael.com/in-unsubtle-critique-israel-gifts-unesco-replica-of-arch-of-titus/


[8] https://www.independent.co.uk/news/world/europe/the-stones-of-paris-403115.html