Index ~~ Background ~~ Purpose ~~ Hypothesis ~~ Materials ~~ Earthquake Machine ~~ Modifications: Overlapping - Height - Buttresses - Base Isolators - Cross Braces - Roofs ~~  Resistant Buildings ~~ Problems ~~ Further Experimentation ~~ Bibliography

STRUCTURAL MODIFICATIONS:

BUTTRESSES AND STABILITY

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PROCEDURE

On the earthquake machine, buttresses were added to a rectangular building. The blocks were not overlapped. Three  blocks were stacked on each of the four corners to act as buttresses. The handles of the earthquake machine were pulled back to the line then let go. When the machine had stopped shaking, the handles were pulled again and again until the building collapsed. Each pull of the machine was timed to last two seconds. Three trials were done. At the end of each trial, the building was rebuilt. The data for each trial was recorded. Three trials were done. Tests were done using straight buttresses and then slanted buttresses.

Buttresses were also tested on cubic buildings where the blocks were overlapped. The same procedure as above was used.

 

Three layer overlapped building with three layer straight buttresses

Straight buttresses

overlapped building

Three layer overlapped building with slanted three layer buttresses

Slanted buttresses

overlapped building

 

Three layer non-overlapped building with three layer straight buttresses

Straight buttresses

non-overlapped building

RESULTS

BUTTRESSES AND STABILITY
NON-OVERLAPPED AND OVERLAPPED BLOCKS
    NO BUTTRESSES STRAIGHT BUTTRESSES SLANTED BUTTRESSES
   

NON-OVER

LAPPED

OVER

LAPPED

NON-OVER

LAPPED

OVER

LAPPED

NON-OVER

LAPPED

OVER

LAPPED

    2 4 8 12 16 6
    2 6 11 6 12 8
    2 6 10 8 14 10
  AVERAGE 2 5.3 9.7 8.7 14 8
   

Improved stability

  385 64 600 51

 

 

CONCLUSION

Reinforcing  the structure with buttresses makes the building more stable. For buildings where the blocks are not overlapped,  straight buttresses improved the stability by 385%. For buildings with slanted buttresses, the increase in stability is 600%.  For buildings with straight buttresses, the building pushed the buttresses forward until they fell off the earthquake machine. The slanted buttresses are harder to move because they are pressing against one another.

For the building where the blocks were overlapped and had straight buttresses, the stability is improved by 64%. Buttresses don’t stabilize the overlapped buildings as much as the non-overlapped buildings. This is because of the arrangement of the blocks in the overlapped buildings already makes them more stable.

 

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