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Bank of America Plaza

Bank of America Plaza

Bank of America Plaza

There’s no way you could have been to Atlanta and not have seen this building. The Bank of America Plaza, or more popularly known as “The Pencil Building” is a prominent feature of Atlanta’s skyline. It boasts not only being the tallest building in Atlanta, but also in the entire southeast region!

When I came to Georgia Tech’s freshman orientation almost three years ago, I remember a student proclaiming, “If you are ever lost, look for ‘The Pencil Building’ and that’s where home is.” As I began adventuring off campus during my freshman year, I always kept that statement in mind; I looked for the pencil building wherever I was and I always found it’s glowing point. When I was returning to Georgia Tech for my sophomore year after a summer at my house in New York, I vividly remembering driving to Georgia Tech from the airport and seeing The Pencil Building in sight. I may have shed a tear… for me The Pencil Building symbolized my return to my new home in Atlanta, Georgia.

Structure Information

Pencil Building in Atlanta, GA [1]

The Bank of America Plaza was built in 1992 and is located on North Avenue in Atlanta; it stands between Midtown and Downtown, representing the dividing line. The building currently serves as office space and has a few restaurants, geared towards the tenants. The architecture firm of Kevin Roche, John Dinkeloo and Associates had designed it, Beers Construction built it, and Shorenstein Properties LLC was funded the construction[2].

Historical Significance

Left to Right: Bank of America Plaza [3], Messeturm [4], Empire State Building [5], Chrysler Building [6]

Designed in the 1990s, the building architecturally demonstrates an Art Deco style. Similar styles to this include the Empire State building and the Chrysler Building, both in New York City and the Messeturm in Frankfurt, Germany shown in the above images. Structurally, the long columns are exaggerated, fabricating a visual effect of leanness. Additionally, all the columns are on the outside perimeter,  creating an open floor plan throughout the offices. The entire tower was built in only 14 months, which is one of the fastest construction schedules for any 1,000 ft building. While there are no specifics on how they constructed the building so quickly, from experience working in the field, I can say this is impressive.

Cultural Significance

During the time when the Bank of America Plaza was built, Atlanta was undergoing a huge transformation. The city was booming, unemployment was low, businesses were prospering, and the 1996 Olympic Games were coming to town. The Olympics gave Atlanta the chance for world recognition and many companies took this as their chance to “tap into Atlanta’s latest potential.” The owners wanted to build a structure to symbolize the new reputation of Atlanta: the city of growth.

While the building was supposed to serve as a symbol of affluence, there were some critics. Urban planners dubbed the name “tower in a park” because they felt that it separates itself from the already built surroundings. There are no street level pedestrian entrance ways and all the retail space can only be entered from the inside, leaving the tenants to be isolated from the outside. One critic called the building’s shaft “unconventional,” while noting that its apex “looks peculiarly like a pencil” [7]. While this critic deemed that the building looking like a pencil was a negative remark, here at Georgia Tech, I think that it is the building’s most notable quality, thus explaining the nickname “The Pencil Building.”

Structural Art

Pencil Building in Atlanta, GA

In order to decide if this building embodies structural art, I first need to define exactly what qualifies as structural art. According to Professor Billington of Princeton University, structural art should be interpreted in terms of the ‘Three S’s’; the scientific, social, and symbolic meaning [8].

The scientific detail will be explained in more detail below, but the Bank of America has eight super columns at each corner of the building. The columns get all the loads from the slabs and from the truss system on top and carry the load down to the foundation. The building is composite meaning it has a mixture of both concrete and steel like many other buildings in Atlanta.

The social role this building plays into society is a limited one. This building was designated as an office space, and with that role it doesn’t separate itself from many of the other downtown buildings in Atlanta. However, it was built during a prosperous time in Atlanta during the 1990s right before the Olympic Games when Atlanta wanted to look good as the whole world would be watching the city. Unfortunately, the building is currently only half occupied which clearly shows that this structure plays a minimal role in the functioning of society.

In a symbolic sense, to me and many others at Georgia Tech, the Bank of America Building symbolizes “home.” Only two blocks away from campus, the building is a literal thumbtack into the map for where Georgia Tech is. Because you can see it from anywhere in Atlanta due to it being the tallest building in Atlanta, it’s a sure way to locate where home is.  Although many people don’t like the design of the building (which I will blame on the architect, not the civil engineer), it is clearly a symbol as in every movie/ TV show that is located in Atlanta always has a scene panning around this building.

As to Billington’s criteria, the structure is not “transparent.” This means that the it isn’t apparent how the loads are being transferred. Starting from the top of the structure, the trusses that create the obelisk shape are very crowded and thin, clearly meant to be an architectural detail. There are so many bars that it was even hard when I was looking at a picture to try and trace how the load was being carried. Side note: the spire at the top is mostly covered in 24 karat gold leaf!! [9] Talk about ornamentation… Once the load reaches the building, it seems as though the load is carried straight down due to the eight super columns. While this is mostly true, I do not think this represents structural art because it seems that the purpose of this façade was to make the building appear taller and slimmer, not to depict it’s function. Due to the fact that the Bank of America Plaza was not built to serve a specific function, but mostly for architectural components, I determined that the Bank of America Plaza is not structural art.

Structural Analysis

The Bank of America building is consistently referred to defeating an extraordinary construction feat as it was only built in 14 months, making this one of the fastest construction schedules for any building over 1,000 feet. To my surprise, despite this feat, neither the structural engineer, CBM Engineers Inc., nor the main contractor, Beers Construction, have any information on this project. The structural material is composite: the core is reinforced concrete, the columns are concrete encased steel, and the floor spans are steel [10]. The Bank of America Plaza was constructed with a composite frame. It was also an early example of the use of super columns, which are actually quite super because the 2 large eight foot square columns at each of the edges of the tower are the only columns that take loads, creating a completely structural column free interior. The super columns are set into the facades of the tower, adding an exterior texture through 8 granite clad points that extend from the base to the crown.

 

Shows how as the height increases, the load decreases.

Loads shown on Bank of America Plaza.

From the figure to the left, it can be assumed that the gold part of the building puts its load onto the rest of the building through the corners. Additionally, from the figure, you can see how the forces flow. Keep in mind the horizontal lines represent the concrete floor slabs and the drawing is not to scale; there are 55 floor slabs in the Bank of America Plaza. From the corners of the structure, the forces flow down through the columns all the way to the bottom concrete footings. Each of the concrete slabs also has their own load. These forces travel to the closest column and join in on the way down to the footings. The Bank of America Plaza was designed with all the load bearing columns to be on the perimeter of the building to provide for open floor plans for office, hence the picture’s two distinct columns in the cross section shown. Shown in the figure on the left, as you go down the building (get closer to the ground) the loads increase. This is because all the columns on the bottom are carrying the self-weight and the weight of everything above it, but at the top, there is less weight to carry.

In addition to acting as a column, the Bank of America building also works as a cantilever. Due to the building being a tall structure (over 1000 feet), wind loads play a role in how the forces affect the structure. Illustrated in the picture below are the forces that are applied to the Bank of America Plaza due to the wind.

 

Illustration showing how the winds loads transfer to the building and can be converted into a cantilever beam.

 

The force of the wind was found in the Georgia State International Building Code and I chose to design for a Risk Category III Hurricane and EF2 Tornado due to the building’s location in Atlanta. Under these conditions, the minimum wind speed to design for is 145 mph [11]. From there I used a wind velocity chart to determine that the pressure is 52.5 psf [12]. Since this pressure was in pounds per square foot, I found the width of the building to be 252.5 feet. Then, by multiplying the width of the building with the pressure per square foot, I found the pressure of the distributed load, 13,258 lbs/ foot. In order to move from the first figure to the second, the building was turned 90 degrees to be symbolized as a cantilevered beam. I then expressed the distributed load as a point load in order to calculate the reactions and moment at the base of the tower.

∑Fy = AY – 13606k = 0

AY = 13606K

∑MA = MA + 136060k (511.5 ft) = 0

MA = -6,959,469 kips∙foot

After making these calculations, I checked my theories on Mastan2. Shown below is the moment diagram and deflected shape of my “beam” aka The Bank of America Plaza. The structural program proves my calculations are accurate and helps illustrate how the largest moment is at the bottom of the tower while the largest deflection is at the top due to wind load.

Mastan2 illustrating the moment diagram of the load.

 

Mastan2 illustrating the deflection of the load.

By stating that the moment at A is a negative moment, it describes that the bean has developed tension in the upper portion because it gets elongated and compression in the lower portion because it gets shortened. This makes sense if we think it through; if there is a giant force of wind on the left side of the building, the deflection will be shown the building bending to the right, describing the scenario above perfectly. Of course, this is all in theory because wind comes from all sides. Also, there are numerous factors to consider including how close the other buildings are to the Bank of America building. If the buildings are close together then there are other buildings that take an extent of the wind load on their own structure.

Strangely enough, I had found no references to this building from the architect, structural engineers, or contractors. It seems as though none of them wanted credit for it. The closest thing I got to a description was from the structural engineer’s project page that states it was built in Atlanta, California…someone needs to fire their intern [13].

Since none of this information was readily available online, I do not think this information was used to communicate the design to the stakeholders. In current times, most stakeholders are only concerned with their cost revenue and the ratio between the cost of building and the cost earned from tenants; their only concern about the structure would then be the cost and to make sure the building doesn’t collapse.

Personal Response

After visiting the Bank of America Plaza, I understand how isolating it could be. There were no doors for me to get inside from the street and the exterior was just a plain brick façade. The main door was through the parking garage, but I felt uncomfortable entering the building since I did not work there. For being my symbol of Atlanta, it did not feel very “homey” in person.

I also never realized how controversial the Bank of America Plaza was until I start researching it. The building was foreclosed in 2012 due to it’s vacancy demonstrating how unwanted it was for an office space. Many people also think that the glowing obelisk at the top is destructive to the skyline and sticks out like a sore thumb. Also, numerous people thought that the building represented either an ugly pencil or a cigarette (yes, cigarette. I never thought of that one! It gets worse at night when the top starts to smoke too…).

Despite all this, I will maintain my positive image of The Pencil Building because whenever I spot the building, it reminds me that Atlanta is home.

References

  1. https://www.atlantadowntown.com/go/bank-of-america-plaza
  2. http://www.skyscrapercenter.com/building/bank-of-america-plaza/429
  3. https://www.tripadvisor.com/Attraction_Review-g60898-d527262-Reviews-Bank_of_America_Plaza-Atlanta_Georgia.html
  4. https://commons.wikimedia.org/wiki/File:01-01-2014_-_Messeturm_-_trade_fair_tower_-_Frankfurt-_Germany_-_05.jpg
  5. https://www.embusyliving.com/2016/06/empirestatebuilding-topoftherock.html
  6. https://www.askideas.com/27-very-amazing-night-view-pictures-of-chrysler-building-manhattan
  7. http://www.atlantamagazine.com/90s/nationsbank-plaza-now-bank-of-america-plaza-rises-up/
  8. http://www.curee.org/CASCE-5/Lectures/L0009.html
  9. https://www.ajc.com/business/bank-america-plaza-becomes-atlanta-priciest-repo/yKEFrl8ElBb2oAiPguIjfJ/
  10. http://www.skyscrapercenter.com/building/bank-of-america-plaza/429
  11. https://dca.ga.gov/sites/default/files/2013_drbc_ibc_appendixn.pdf
  12. http://www.nctlinc.com/velocity-chart/
  13. http://www.cbmengineers.com/project_bank_of_america_plaza.html

Comments

  1. rlakhani7 says

    I was actually going to choose this structure to do the blog on because of its unique name, “Pencil Building”. I am also glad to see that you used Mastan to prove and derive your results and the explanation then makes sense. By the design parameter you choose, if you were the designer of this structure, how would you assess the costs of the structure? In other words, do you put sole emphasis on the building failing or collapsing due to wind loads only or any other loads?

    • ezaruvinsky3 says

      If the building were to fail, I would say it would be due to wind loads only. Even though the structure was built in record time (14 months), there is not too much innovation with the design. In other words, the structure has been tried before and shouldn’t fail. But what could cause it to fail are the variables of where the building is located. Wind is a variability because we can never exactly predict it and we cannot brace all of our structures for super storms.