The Louvre glass pyramid in Paris is an intricate fusion of traditional and modern architecture. It stands at the core of the Cour Napoleon courtyard of the Louvre Museum. Just beneath the pyramid is the lobby that connects the museum's three pavilions - Denon, Richelieu, and Sully.
The Louvre pyramid is the main entrance to the museum built with the purpose of providing larger space for the visitors to descend into the lobby below.
The construction of the glass pyramid was a part of the project named 'Grand Louvre' which was commissioned by the President of France in 1984. The prime focus of the project was on expanding and modernizing the Louvre Museum. The construction of the pyramid was completed in 1989.
The Louvre pyramid was designed by Ieoh Ming Pei, a Chinese-American architect. He was also the founder of Pei Cobb Freed and Partners.
The structure was engineered by Nicolet Chartrand Knoll Ltd. of Montreal in terms of design consultancy and Rice Francis Ritchie of France in the construction phase.
2. Structural Details
A technique known as "structural glazing" has been used in the framework of the Louvre pyramid. This technique consists of anchoring glass segments on a metal mesh to form gigantic installations. This is also used at a smaller scale in home furnishings and showrooms.
In structural glazing, the external surface of the glass is fully exposed and it is only attached to the underlying framework with the help of sealants. A coating of flourine carbon lacquer has been used in case of the Louvre pyramid.
This technique not only creates an appealing and unique exterior but also allows more natural light to enter the structure.
However, this effect is not possible to achieve with all types of glasses. The makers of the Louvre pyramid ordered a special type of extra-clear glass from Saint Gobain, now called Diamant glass.
2.1 Diamant Glass
Diamant glass owes its high transparency to lower iron content as compared to normal glass. Iron oxide present in the glass gives it the common greenish tint which was diminished to the maximum extent in Diamant glass.
The Diamant glass offers the following benefits:
- Visual Comfort: The extra clear glass allows more daylight to pass through it by reducing sunlight absorption. This results in a clearer vision for the occupants.
- Aesthetics: In large multi-layer glass structures, clear and ample daylight improves illumination and gives an ornamental appearance.
- Environment friendly: No artificial light is required in the daytime, saving electricity consumption to a certain extent.
- Sturdy: Even to this date no glass panel of the Louvre glass pyramid has shattered or cracked. This sturdiness results in low replacement costs.
Architect I.M. Pei did not want the glass pyramid to steal the Louvre museum's limelight. By using the specially discolored Diamant glass, the view of the museum did not get obstructed and the purpose of constructing the pyramid was also fulfilled.
2.2 The Framework
The square base of the Louvre glass pyramid has sides measuring 112 ft each and a base area of 11,000 sq. ft. The apex of the pyramid is 71 ft high from the center of the base.
The framing structure is made up of 6,000 bars of structural steel and aluminum. This network comprises of 2,100 nodes and weighs nearly 100 metric tons.
In the inner frame, there are 675 diamond-shaped and 118 triangular steel panes in total. These panes are connected by 128 steel girders and 16 steel cables. The outer frame, on the other hand, comprises glass segments fixed to extruded aluminum panes.
The aluminum frame and the steel structure are connected by a gib screw and steel bracket setup, which enables the movement of the frame in three directions. This makes the entire structure both sturdy and flexible at the same time.
The overall weight of the Louvre pyramid is 180 metric tons.
The main pyramid is surrounded by three similar but smaller pyramids. These were built to add balance to the scenery and to further increase the illumination and ventilation in the lobby below.
The Louvre glass pyramid was completed in 1989.
It was built to increase the area of the entrance to the museum to facilitate easier entry for the visitors. It is now the main and largest entrance to the museum.
According to I.M. Pei, the silhouette of the Louvre museum did not have any curve. Hence, all curved shapes such as spheres, hemispheres were taken off the list. Even cubes were not too suitable. In the end, the pyramidal shape was finalised as the most appropriate choice.