Blog 3
Grande Arche de la Défense (Great Arch of Defense)

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

References

[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/