GOLD

Love Waves

Testing what shape of structure could withstand earthquakes (love waves) best.
Konrad Gierus
Grade 7

Hypothesis

Purpose

We wanted to create a house resistant to earthquakes. This should inform others how you can build a specific structure that can endure an earthquake.  

To design an earthquake-resistant block structure.

 

Hypothesis

  1. A brick pattern structure will survive a higher amplitude earthquake.
  2. A Star pattern structure (every layer rotated  45°) will survive a higher amplitude  earthquake.
  3. Placing the blocks closer to the middle in the  structure will survive a higher amplitude earthquake.

 

Research

Background

Ideas for earthquake resistant buildings:
 

If you put a stick through the center of a building it will more likely not fall because, if the building does start to tilt, the stick will stop the building from falling.

If you build an airbag that will detect and fill up when an earthquake is near, it will highly decrease the effect of the tremor.

If you put thick string tightly around the building, it will also decrease the effect.

Image result for spider web building that resists earthquakes

If the building has rubber on the bottom (very flexible),  then if a tremor hits, the rubber moves, not the building.

 

 

How earthquakes move the ground?

  • Surface waves travel over the Earth's surface:
    • Rayleigh waves, also called the ground roll, travel like ocean waves over the surface of the Earth, moving the ground surface up and down. They cause most of the shaking at the ground surface during an earthquake( Secondary waves or S waves; slower).
    • Love waves are fast and move the ground from side to side.(Primary waves or P waves; fastest. In this project I am testing P waves).
    • .
  • Body waves travel through the Earth.

Variables

Variables

Manipulated = Structure design

Controlled = Structure height, number of blocks used, metronome

Responding = What earthquake amplitude and/or RPM makes structure fall

 

Procedure

Materials

COMPUTER & BLENDER SOFTWARE

Logo — blender.org

KEVA AND TINY BLOCKS

RULER & WHITE SURFACE (The ruler guided the surface back and forth).

RPM MACHINE

Procedure

 

  1. Designed 15 different block structures with 24 blocks 

(6 levels with 4 blocks per level 6x4)

Part 1 (Blender simulation - 3D creation, animation, and simulation software):

  1. Created a moveable surface. 
  2. Recreated the structures on the surface.
  3. Set up a simulation that moves the surface horizontally to recreate an earthquake.
  4. Increased amplitude of the horizontal movement until each structure fell. 
  5. Recorded at what amplitude each structure fell.
    Structure Failure = 4 Blocks off

Part 2 ( Keva & tiny wooden blocks)

  1. Set up moveable surface against a long, metal ruler.
  2. Built structure on surface out of Keva blocks or tiny blocks.
  3. Move surface with structure on it horizontally with the ruler as our guide.
  4. Increased amplitude of the horizontal movement until each structure fell. 
  5. Recorded at what amplitude each structure fell.
    Structure Failure = 4 Blocks off
  6. Repeated 7 - 11 six times for each structure design.

    Part 3 (Testing best structure again with aid from metranome).

  7. Rebuilt 8 of the best structures on the moveable surface.
  8. Set up a metronome.
  9. With the ruler and metronome as our guide, we moved the surface with structure on it horizontally at the pace of the metronome.
  10. Increased amplitude of the horizontal movement until each structure fell. 
  11. Record at which amplitude each structure fell.
    Structure Failure = 4 Blocks off

 

Shape Number

Top view

3D view

Description

Photo

Shape 1

No overlap/four independent stacks.

Shape 2

No overlap/four independent stacks.

Shape 3

Overlap/brick pattern.

Shape 4

Every layer rotated 45°/star pattern.

Shape 5

No overlap but rotated 45°/star pattern.

Shape 6

Overlap/brick pattern + every layer rotated 45°/star pattern.

Shape 7

No overlap/four individual stacks.

Shape 8

No overlap/four individual stacks.

Shape 9

No overlap/four individual stacks.

Shape 10

overlap/brick pattern.

Shape 11

overlap/brick pattern.

 

Shape 12

Overlap/brick pattern.

Against the law of gravity.

Shape 13

Overlap/star pattern.

Shape 14

Overlap/star pattern.

Shape 15

Overlap/star pattern.

Against the law of gravity.

Observations

 

Raw Data

For every shape, I did a virtual test on Blender, a test in the real world with tiny blocks and with KEVA blocks. 

  Blender Tests KEVA Tests      

survived metronome

 

shape

virtual (meters)

Trial 1 (inches)

trial 2 (inches)

average

trial tiny (inch)

trial 1 (inch)

trial 2 (inch)

trial 3 (inch)

avradged fail(inch)

1

0.11

5

3

4

1

       

2

0.14

5

3

4

1

       

3

1.4

8

10

9

5

10

12

14

12

4

1.7

7

7

7

3

12

18

14

14.7

5

1.9

7

7

7

2

12

13

13

12.7

6

1.8

6

6

6

3

12

12

15

13

7

0.22

5

2

3.5

1

       

8

0.16

5

4

4.5

1

       

9

0.23

4

5

4.5

1

       

10

1.7

7

7

7

2

11

11

13

11.7

11

1.9

5

6

5.5

2

15

14

13

14

12

0.001

0

0

0

0

       

13

2

6

6

6

1

16

15

15

15.3

14

0.003

5

7

6

1

       

15

0.001

0

0

0

0

       

 

Analysis

Results

General Observations

  • Walls that were stacked upon each other were more likely to fail than those walls that were twisting around
  • The closer to the middle the block are, the longer it lasts (not the exact middle).
  • If you put the blocks too much in the middle, they are more likely to fall as they are extremely unstable.

     

Does brick pattern help?

In every trial (virtual, keva blocks and tiny blocks) the brick pattern (shape 3) survived a higher amplitude.  The brick pattern allows for connection between the blocks.

Hypothesis 1 = correct.


Does star pattern help?

In every trial (virtual, Keva blocks and tiny blocks) the star pattern survived a higher amplitude.  The star pattern allows for even more connection between the blocks.

Hypothesis 2 = correct.


 

Does having the blocks closer to the middle help?

Generally, the structures with the blocks closer to the middle survived a higher amplitude(but only to a point). If the blocks were too close to the middle, the structures didn’t do too well in the earthquake. This is probably due to the fact that the blocks were not balanced as the blocks were placed closer and closer to middle.

Hypothesis 3 = partly correct.

Conclusion

The best structure designs are designs number #13 and #3 because they are overlapping therefore they are the best. #13 is good because it is also in star pattern and has more friction.

Shape 13

 

 


 
Shape 3

 

 

Application

We can make use of the knowledge we discovered in the process of this experiment by implementing it in future buildings in locations vulnerable to earthquakes Ex. Vancouver island.

.

Japan after earthquake, 2011

 

We may also apply the method we used (doing multiple experiments with different designs, materials, RPM, roughness of earthquake, etc.), as a firm use of the scientific method in our future experiments.

 

Sources Of Error

  • Human error: not able to consistently stop at, for example, 2 inches
  • Block error: not able to create perfect structures, the inconsistency of materials (real-world and virtual)
  • Human error: unable to perfectly predict the amplitudeof which the structures failed at; I moved surface to only whole numbers.

Improvments

  • Use machines to move the surface
  • Test Rayleigh waves.

 

Citations

Bibliography

  • En.wikipedia.org. (2020). Earthquake. [online] Available at: https://en.wikipedia.org/wiki/Earthquake 
  • Asme.org. (2020). Made in Japan: Earthquake-Proof Homes. [online] Available at: https://www.asme.org/topics-resources/content/made-in-japan-earthquake-proof-homes 
  • Google.com. (2020). metranome - Google Search. [online] Available at: https://www.google.com/search?q=metranome&rlz=1C1CHBF_enCA882CA882&oq=metranom  
  • Windows2universe.org. (2020). Seismic Waves: Moving and Shaking During an Earthquake - Windows to the Universe. [online] Available at: https://www.windows2universe.org/earth/geology/quake_4.html 
  • Cite this for Me | Free Reference Generator – Harvard, APA, MLA, Chicago... (2020). FREE Citation Machine: Accurate & Easy-to-Use | Cite This For Me. [online] Available at: http://www.citethisforme.com/ca/citation-generator .
  • Encyclopedia Britannica. 2021. Discern between body and surface waves, primary and secondary waves, and Love and Rayleigh waves. [online] Available at: <https://www.britannica.com/video/181934/rock-vibrations-Earth-earthquake-waves-P-surface#>

Acknowledgement

Thanks to Matthew Paisley for taking us to SAIT for experiments.

Thanks to Bogusia Gierus for being the photographer and teaching us the scientific method.

Thanks to Alex Gierus, for motivating me to utilize the 3d software, Blender, for this project and for being supportive all the way through. 

Thanks to Jeremy Paisly for being an amazing colleague, who unfortunatly could not make it this year.