Jump to main content

Building the Tallest Tower

1
2
3
4
5
1,646 reviews

Abstract

Skyscrapers are impressive structures. What does it take to design a building so tall? Engineers use strong materials and innovative design to push the limits of gravity. They use special tables to simulate earthquakes and test models of their buildings. In this project, you will build your own earthquake table and see how tall you can make a tower out of LEGO® bricks. You can even measure how hard your earthquake table shakes using the accelerometer of your smartphone and a sensor app.

Summary

Areas of Science
Difficulty
 
Time Required
Short (2-5 days)
Prerequisites
None
Material Availability
Readily available
Cost
Low ($20 - $50)
Safety
No issues
Credits

Sara Agee, PhD, Science Buddies
Edited by Ben Finio, PhD, Science Buddies

LEGO is a registered trademark of the LEGO Group.

This project idea is based on a simple design for a shake-table posted on RAFT, the Learning with LEGO PEER project at UC Irvine, and science fair projects posted from Selah Intermediate School in Selah, WA:
  • RAFT, 2014. Shake Table for Testing Structures in Earthquake Country, Resource Area for Teaching (RAFT), San Jose, CA. Retrieved August 17, 2017.
  • PEER, Date Unknown. Learning With LEGO: School-University Partnership (SUP) for Earthquake Engineering Education, Pacific Earthquake Engineering Research Center (PEER). Retrieved August 17, 2017.
  • M., Ben, 2005. "The Effect of Wind Load on a Building ," Selah Intermediate School, Selah, WA. Retrieved March 6, 2007, from this URL, but no longer available online: http://www.selah.k12.wa.us/SOAR/SciProj2006/BenM.html
  • G., Krista, 2002. "The Effect of Structural Height on Building Stability," Selah Intermediate School, Selah, WA. Retrieved March 6, 2007, from this URL, but no longer available online: http://www.selah.k12.wa.us/soar/sciproj2002/KristaG.html

Objective

In this experiment you will make a shake-table to test if the height of a building will affect its stability.

Introduction

As of 2017, the tallest building in the world is the Burj Khalifa in the United Arab Emirates (Figure 1), with a height of 828 meters (2,717 feet). Over the decades, different cities and countries have competed with each other to build taller buildings. The Burj Khalifa has surpassed other buildings like Taipei 101 in Taiwan (508 m/1,667 ft), the Petronas Towers in Malaysia (451.9 m/1,483 ft) and the Willis Tower in Chicago (442.1 m/1,450 ft) to claim the title of world's tallest building. How do engineers build buildings so tall?

Photo of the Burj Khalifa in the United Arab Emirates
Figure 1. The Burj Khalifa in the city of Dubai, United Arab Emirates (Wikipedia user Donaldytong).

An engineer designs a building to withstand forces, or things that push and pull on the building. Forces come from many sources: gravity, people inside, weight of building materials, weather, and environmental impacts. If the design is stable, then these forces will not weaken the structure or cause the structure to collapse.

One type of force that can weaken a structure is a lateral (side-to-side) shaking force, like that experienced during an earthquake. Earthquakes occur when the earth's tectonic plates, which are slowly moving relative to each other, get stuck for a while and then suddenly come loose. If an engineer is going to design a building in earthquake country, then they need to be sure that their design can withstand lateral forces. Some of the world's tallest buildings, like the Petronas Towers, are an excellent example of this type of design because Malaysia is in an area that experiences frequent earthquake activity.

One way to test a design for stability to lateral forces is to use a shake table. A shake table is a special type of table that engineers use to simulate an earthquake on model buildings. One very large shake table is at the Pacific Earthquake Engineering Research Center (PEER) at the Department of Civil and Environmental Engineering, University of California, Irvine. Here, they host an annual contest where student teams build and test their LEGO® buildings for stability (Figure 2).

Three men use LEGOs to construct buildings of various shapes and sizes

A table is filled with LEGO buildings, some of which have collapsed or fallen over
Figure 2. At UC Irvine, students at the Learning With LEGO program get to see if their LEGO structures can handle the shake-table. You can see the LEGO structures before and after the shake (photos from PEER, Date Unknown).

In this experiment, you will build your own miniature shake-table which you will use to test your own LEGO buildings. By building structures of different heights, you will test if increasing the height of the structure has an effect on the stability of the building. You also have the option to measure how hard your earthquake table shakes using the accelerometer of a smartphone and a sensor app. Will your designs be able to take a shake?

Terms and Concepts

You should be familiar with these terms from the introduction:

Additional terms for students using a sensor app:

Questions

Bibliography

Read all about famous skyscrapers around the world at this site from the PBS series "Building Big":

Here is a simple design for a shake-table that you will use in this experiment:

One inspiration for this project came from the Learning With LEGO program developed by the Pacific Earthquake Engineering Research Center (PEER) at the Department of Civil and Environmental Engineering, University of California, Irvine:

Here are two science fair projects from students at the Selah Intermediate School in Selah, Washington that inspired this project idea:

  • M., Ben, 2005. "The Effect of Wind Load on a Building ," Selah Intermediate School, Selah, WA. Retrieved March 6, 2007, from this URL, but no longer available online: http://www.selah.k12.wa.us/SOAR/SciProj2006/BenM.html
  • G., Krista, 2002. "The Effect of Structural Height on Building Stability," Selah Intermediate School, Selah, WA. Retrieved March 6, 2007, from this URL, but no longer available online: http://www.selah.k12.wa.us/soar/sciproj2002/KristaG.html

Materials and Equipment

Experimental Procedure

Note: In this science project, you will build your own shake table and test the strength of LEGO towers. Optionally, you can also measure the strength of your simulated earthquakes using a smartphone equipped with a sensor app. Here are the instructions on how to measure the earthquake strength.

Building Your Shake Table and LEGO towers

  1. Cover the edges of the plexiglass sheets with duct tape. This will prevent the sharp edges from cutting the rubber bands.
  2. Place the two plexiglass sheets on top of one another.
  3. "Rubber band" the two together by stretching a rubber band around each end, about 1 inch from the edge of the sheets.
  4. Insert the rubber balls between the boards at each corner, placing them directly under the rubber bands (this will help prevent the sheets from bending).
  5. The shake-table should now be assembled as shown Figure 3.
Diagram of two plexiglass sheets separated by rubber balls at each corner and held together with rubber bands
Figure 3. A simple shake-table design you can use for this experiment.
  1. Attach a large, flat LEGO mounting plate to the top of your shake-table by slipping it underneath the rubber bands. This will be where you mount your structures to the shake-table.
  2. Build a series of LEGO towers of increasing height (if you do not have enough bricks, you can build and test the towers one at at a time). You should use the same base pattern for each tower, so that the size of the tower's footprint does not change and only the height will be different. You can double check this after you are finished by measuring the length and width of the base of each tower, and they should be the same.
  3. Measure the height of each tower in centimeters (cm) with the measuring stick. Write the height of each tower in a data table like Table 1.
Tower Height Table Displacement (cm) Did it Fall? (Y/N)
     
     
     
Table 1. Example data table.

Testing Your LEGO Tower Stability

  1. To test each tower:
    1. Place it in the center of the top surface of the shake-table.
    2. Have someone else hold the bottom piece of plexiglass firmly in place, or use C-clamps to clamp it to a table so it does not move.
    3. Pull the top layer of the shake-table out of alignment, as shown in Figure 4. Measure the distance between the edges of the two layers and record this value in your data table. This distance is called the "displacement."
    4. Quickly release the top layer of the shake table and allow the rubber bands to snap it back into place. Does your tower fall? Record your observation in your data table.
Two plexiglass sheets are moved parallel to each other and the displacement between them is measured
Figure 4. How to create displacement to simulate an earthquake with your shake table.
  1. Test each tower with increasing displacement values until you find out when the tower will fall.
  2. Compare your results. Did all of the towers fall at the same displacement values or were there differences? Did tall towers have different values than short towers?

Optional: Measuring Earthquake Strength with a Sensor App

Scientists use instruments called seismometers to measure the motion of the ground during earthquakes. In this project, you can use a similar (but not identical) device called an accelerometer to measure the motion of the top plate of your shake table. An accelerometer measures acceleration, or how fast an object's velocity changes. Accelerometers are built-in to many smartphones and video game controllers to give them motion control. You can use a sensor app such as phyphox to record data with your phone's accelerometer. Then, try out this procedure:

  1. Use LEGO bricks to build walls to keep your phone in place on top of the base plate, as shown in Figure 5. The phone should lay flat with its screen facing up, and it should be held tightly in place, without sliding around. If the phone can slide around and slam into the walls, this will affect your data. Use additional rubber bands as padding if necessary to hold the phone firmly in place.
A smartphone is placed on a plexiglass sheet next to a building made of LEGOs
Figure 5. Phone held in place with LEGO bricks and a rubber band for padding.
  1. If you use the phyphox app, open the accelerometer with g function. Press on the accelerometer graph that represents the direction you would like to measure, based on which way you will displace your shake table (for example, select the X accelerometer graph if the phone will be shaking side-to-side).
  2. When you pull back the top plate of your shake table, press the play button in the app to start a recording before you let go.
  3. Press the pause button to stop recording after your shake table has stopped moving. Make sure to save your data.
  4. Review your graph and if necessary zoom in on the part where the table shakes. Your data should look something like in Figure 6.
Example graph of acceleration over time

A graph measures the acceleration of a building as it shakes on a tabletop. The initial shaking of the tabletop causes large spikes at the beginning of the graph that slowly level out as the shaking subsides. The minimum value of the graph is -9,5 and the maximum value is 9.2 meters per second squared.


Figure 6. Example data recorded with phyphox and a homemade shake table. The x-axis of the graph is time in seconds and the y-axis is acceleration in meters per second squared.
  1. Add columns to your data table (Table 1) for the minimum and maximum acceleration values. Then, use the 'pick data' tool in phyphox to select the maximum and minimum data points in your graph. Once you have selected a data point, the app will display its x- and y-values. Record the minimum and maximum acceleration values in your data table.
    1. How do these values relate to the displacement of the top plate of your shake table? In other words, when you move the plate farther and stretch the rubber bands more, do the minimum and maximum accelerations stay the same, get bigger, or get smaller?
    2. How do these values relate to whether or not your building falls over? Are buildings more likely to survive high accelerations or low accelerations?
icon scientific method

Ask an Expert

Do you have specific questions about your science project? Our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.

Global Connections

The United Nations Sustainable Development Goals (UNSDGs) are a blueprint to achieve a better and more sustainable future for all.

This project explores topics key to Industry, Innovation and Infrastructure: Build resilient infrastructure, promote sustainable industrialization and foster innovation.

Variations

  • In this experiment you made the footprint of each tower the same, and only changed the height. Do you think that by changing the footprint you could make taller buildings more stable? Try making taller buildings with different sized bases to test this idea.
  • Another factor is the ratio of the area of the base of the building to the height of the building. You can calculate the area of the base by multiplying the length times the width in centimeters. Then you can calculate the ratio by making a fraction of base:height. Build different towers with different ratios and test them on your shake-table.
  • Try building towers out of a different material that allows you to test different structural designs. Good ideas are using straws, popsicle sticks, or toothpicks and marshmallows. Try comparing square designs to triangular or hexagonal designs. Try adding extra structural elements to your design. Can you design a more stable tower? How tall can you build it before it loses stability?
  • If you used a sensor app for your project, look up the relationship between acceleration and force (hint: search for "Newton's second law of motion"). What happens to the forces on a building when the acceleration is higher? Does this help explain your results?

Careers

If you like this project, you might enjoy exploring these related careers:

Career Profile
If you turned on a faucet, used a bathroom, or visited a public space (like a road, a building, or a bridge) today, then you've used or visited a project that civil engineers helped to design and build. Civil engineers work to improve travel and commerce, provide people with safe drinking water and sanitation, and protect communities from earthquakes and floods. This important and ancient work is combined with a desire to make structures that are as beautiful and environmentally sound, as they… Read more
Career Profile
Do you dream of building big? Civil engineering technicians help build some of the largest structures in the world—from buildings, bridges, and dams to highways, airfields, and wastewater treatment facilities. Many of these construction projects are "public works," meaning they strengthen and benefit a community, state, or the nation. Read more
Career Profile
The essayist and poet Ralph Waldo Emerson called Greek architecture the "flowering of geometry." Architects blend art and science, designing structures for people, such as houses, apartments, schools, stores, malls, offices, places of worship, museums, sports stadiums, music theaters, and convention centers. Their designs must take into account not only the structure's appearance, but its safety, function, environmental impact, and cost. Architects often participate in all phases of design,… Read more

News Feed on This Topic

 
, ,

Cite This Page

General citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.

MLA Style

Science Buddies Staff. "Building the Tallest Tower." Science Buddies, 18 Nov. 2021, https://www.sciencebuddies.org/science-fair-projects/project-ideas/CE_p013/civil-engineering/building-the-tallest-tower?from=Blog. Accessed 19 Mar. 2024.

APA Style

Science Buddies Staff. (2021, November 18). Building the Tallest Tower. Retrieved from https://www.sciencebuddies.org/science-fair-projects/project-ideas/CE_p013/civil-engineering/building-the-tallest-tower?from=Blog


Last edit date: 2021-11-18
Top
We use cookies and those of third party providers to deliver the best possible web experience and to compile statistics.
By continuing and using the site, including the landing page, you agree to our Privacy Policy and Terms of Use.
OK, got it
Free science fair projects.