An overview of the project
Around the world approximately 20,000 people die each year because of earthquakes. Majority of earthquakes are caused by buildings collapsing which not only has an impact during the earthquake but can leave many homeless or trapped under rubble. Our task was to design and create a building that could withstand a major earthquake following a list of criteria which was:
- have a minimum height of 60cm
- have a maximum base of 30cm by 30cm
- a flat platform of at least 5cm by 5cm
- remain standing after a simulated earthquake
- is constructed from spaghetti and bluetack
- costs less than $60 to build with 1 stick of spaghetti costing $1 and 1 gram of blue tack $1
- The model can be attached to the board
Engineering process
Defining the problem
We need to build a structure that withstands a major earthquake which is simulated by shaking the structure. This structure must follow the criteria of being a minimum of 60cm tall and a maximum base of 30cm by 30cm. To make this structure it must cost less than $60 with 1 piece of spaghetti costing $1 and 1g of bluetack costing $1. We are doing this because it can help us to be more prepared for earthquakes which can result in less damage if an earthquake hits.
Brainstorm and Research
To make a final decision on what to make we did research to help us to decide which was the most effective.
- Cross-brace spaghetti to help distribute energy throughout the tower
- Make the base larger than the top like a square-based pyramid
- The larger the base the more stable the tower
- Make the base strong so it can hold the weight of the rest of the tower
- Triangles are strong because the angles are fixed and all sides support each other
- Hexagons are also strong shapes but not as strong as triangles because they rely on the strength of the joints while triangles rely on the strength of the member with the joints being a simple pin connection. It is easier and more reliable to provide a strong member than a strong joint
- If the building can move it can absorb the energy without falling over
- Pendulums can be used to oppose the force of the earthquake
- Putting multiple spaghetti sticks together can make the tower stronger than if it was just one stick
Design
We went with the general shape of a triangle because it is the strongest as all the sides support each other. We also wanted to add cross bracing so that within each side it was all supported. We also went with the idea that the base should be larger than the top because it is hard to make it exactly straight up and it can easily tip one way also this way the top of the tower doesn’t weigh as much as the bottom. In this final design, we decided to allocate $40 for spaghetti and $20 for bluetack because we calculated that we would need approximately 40 sticks to build it.
Create, Test and Improve
During the building process we could trade in broken pieces of pasta for a whole new piece of pasta. This saved us lots of money as we had to break lots of spaghetti pieces too smaller lengths so it would be more accurate for our tower. We also realised we needed less bluetack than we originally thought and were able to save money there. As we were building we realised that each level was twisting in one direction so we decided to cross-brace across the levels on the higher levels so that it wouldn’t twist and fall into each other and collapse in the middle.
During our tests we looked for any points that looked unstable or were wobbling too much so we could reinforce them with spaghetti or bluetack. Thankfully with the money we had saved from trading in many small broken pieces of spaghetti we had over $10 left. We kept testing as we made changes and added levels and noticed that the more levels we added the more and more it was leaning and we decided we didn’t want to go too much over 60cm as we thought that we shouldn’t compromise the stableness of the tower so it could be taller.
Final Test
This is the final test with our model and it stood throughout the test but starts falling over at the end of the video. You can see it leaning to the right as the spaghetti falls through the bluetack on one of the lower levels which we could prevent next time by adding more bluetack.
Final Reflection
Overall I think the project went well and our tower fit the criteria of the task. At the end of the project we spent $41 on spaghetti and $15 on bluetack with $4 remaining. This is relatively accurate to what we had planned for and I think this was due to the detail of planning the tower and counting how many sticks of spaghetti we would expect to use. Something I thought we did really well was our communication and teamwork as the project was completed well despite multiple of our group members missing lessons and everyone having a part in both the designing and building process. I think that next time if we were to do this again I would try to make sure that everything was done as accurately as possible and so we didn’t have to keep shorting levels to try align it so it wasn’t on an angle.