Spaghetti Structure

Brief Information

An earthquake is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth’s lithosphere that creates seismic waves. These earthquakes can cause destructive damage towards cities and the buildings inside of it. For example, an earthquake of a magnitude of 7.8, struck Nepal in 2015, many citizens were injured and killed by falling rubble, and many were left homeless. Two years after the Nepal earthquake, less than 5% of the destroyed houses had been rebuilt. Which led to 800,000 families being forced to live in temporary shelters. Therefore, it came to the attention of many engineers and scientists that it is principal focus that they research how to create earthquake proof buildings.

In the Year 9 Science Engineering Challenge, groups were tasked with constructing a scale model of an Earthquake- resistant building. During the process, documenting our prototypes and researching other ways engineers have tackled this task.

Our Group

Our group consisted of 4 members, Nicholas Mulcahay, Marshall Tomlinson, Lucas Trim and Myself, all had the mindset that the task was going to be a challenge but determined to complete it. As a group, we all mentioned our strengths and weaknesses and what we could bring to the group, therefore we assigned ourselves specific roles in the task.

Nicholas was assigned the role of documenting the whole process. He was assigned this role due to the fact that he was great and getting good angle shots of each thing we were doing, for example when we made our first scale model of the spaghetti structure, he was quick to get his computer up and photograph from different angles. He also photographed each sketch and detailed designs we completed. Nicholas was very organised in all of his documentation, whenever he photographed something, he would caption the photo and upload it to our collaborative OneNote page in which we could use.

Marshall and Lucas shared the role of building the spaghetti structure, the two of them were exceptionally great at using their fingers carefully and using the correct materials according to the sketch model. The two of them collaborated really well, I would compare the two with a Surgeon and an Operating room nurse, the two have to have each other by there side while doing very hard tasks, Marshall making sure that the whole build was still and making sure that there was spaghetti and blue-tack in hand, ready to use, and for Lucas, he needed Marshall to support him while he was dead-focused on attaching each spaghetti piece in place while making sure it doesn’t break.

Lastly, I was assigned with the role of researching designs of earthquake-resistant structures and how engineers tackled this problem. I shared with the group my ideas and we executed the process. Along the way, I made sure that everyone was on the same page, and that we all stayed on task. I created the detailed design of the structure and calculated the costs. Whenever we had a problem, I provided ideas on how we can move forward from the problem, and get back to the drawing board.

As a whole group, we made decisions based on the majority and made sure we did not disregard anyone’s opinions or ideas, we all brainstormed at the start of the lesson, set out goals for us to complete by the end of the lesson, and made sure everyone was up to the same page.

What is the Challenge and Why?

In groups, create a scale model of a building that is earthquake-resistant. The simulation is the shake test. The shake test is a representation of a 7-8 Magnitude Earthquake, the simulation will go for 10 seconds and if your building does not collapse, your building is “Earthquake-resistant” The building must go under these requirements:

• Has a minimum height of 60cm and a maximum base of 30cmx30cm
• constructed from the materials supplied our teacher (spaghetti and blue-tack)
• Costs less than $60 to build

The challenge given to us is helping us understand the importance of building an earthquake-resistant building, and with the spending limits, it shows that in the real world, useful materials are scarce and expensive. As a group, we learnt that challenges can be overcome by having a test prototype to learn off, it is important to have sketches and drawings so we know what to do when building, and how to work as a team in different roles.

Research

To start off, we searched through the internet finding information about shape, structure, and base. According to many sources it specifies that the triangle is the strongest as it holds it’s shape and has a base which is very strong and also has a strong support. Also, engineers have identified four main aspects of a building that will assist it become earthquake-resistant:

• Diaphragms – the primary component of a building’s horizontal structure, including the floors and the roof. Diaphragms must be placed on their own deck and strengthened horizontally to share forces with vertical structures.
• Cross-Bracing – Engineers have incorporated a variety of columns, braces and beams to transfer seismic forces back to the ground. Cross braces incorporate two diagonal sections usually shaped in an X to build wall trusses.
• Shear Walls – To help resistance swaying force, engineers use vertical walls, to stiffen structural frame of the building. Shear walls are in place of braved framers or in addition to them.
• Moment Resisting Frames – Since shear walls limit a building’s flexibility, some designers choose moment-resisting frames to allow positive movement.

Design

As a group, we all drew detailed sketches on different designs and structures. This was due to us knowing that we couldn’t just rely on one design if the first one failed.

The Main problems that we faced during the first prototype was that we used two much money on the structure and not enough on the support factor (cross beams, shear walls, and diaphragms). How we solved this problem was through cutting down the amount of blue-tack needed from 20 down to 12. Instead of having the original cross beams, we sort of made a half X beam connecting the two support walls. Our Support beam through the middle was cut down to only 2 strands of spaghetti which increased the money we were aloud to spend.

Our price coming to a total of $59.5, consisting of spaghetti that costed $47.5 and $12 worth of blue-tack. The final shape of the building was a rectangular prism with semi-cross beams and a support beam in the middle.

Creation

Each person in the group playing their role so that the process of creating our structure was going to not only be efficient as possible, but also making sure that we didn’t break any pieces of spaghetti. Also making sure that we knew that the blue-tack was scarce.

Testing

Our class’ controlled variable’s were

1. The Teacher simulating the shake test
2. Simulation went on for 10 seconds

When we tested our model, it passed the test of being earthquake-resistant. The shake test represented the primary and secondary shock waves of an earthquake. Our building was not damaged in any way or form, and I think it was due to the cross beams that was added in our building, allowing the transfer of movement to be spread away from the foundation. Our Lego Blue Ninja fell over though 🙁

Reflection

Our outcome was very positive as our earthquake-resistant building was a success against the shake test which was a mimic of an earthquake with a magnitude of an average of 7-8 on the Richter Scale. Also having absolutely no damage dealt during and after the 10 seconds of the shake test.

After analysing the shake test and how our building responded to it, I am going to come to a conclusion that it was the shear walls which allowed flexibility while also bringing strength to the structure that helped the building stay in-tact. Although the cross beams helped the structure a lot, from the shake test, you could tell that there was still a lot of pressure going into the support beams, etc. Which was supposed to be the cross beams job (helping the transfer of movement away from support) The light roof and cross beams on top helped the building stay in-tact, meaning that the weight of the building was low to the ground, low centre of gravity, and more support.

Although our building was under budget, I think our group could’ve revamped the design to make it less wide to decrease the amount of spaghetti needed, which would increase our breathing room of how much money we could spend.

What would I do differently next time?

A most obvious of something that I would do next time is not go for a rectangular base prism as it is not compact and can be expensive to create. I would change to a small square based pyramid with cross beams intersecting in the middle. Also, we had the intention that it was a minimum of 30 cm along the base, which affected our whole process, so I would’ve deficiently decreased the length and width of our build.

Collaboration

Our team work was good at times, but also could be better at times. Although we never had arguments about decisions on the building, our conversations were usually off topic. Saying that we are all in the same basketball team, it was hard not to talk about the game we had last night, or something that is happening in the NBA. If we had not wasted the valuable time we had in class, possibly we could’ve created a better model.

Overall, when assigned in our roles, we all exceeded in them. For example, Nicholas always being proactive to get his computer up and taking pictures of our progress, and uploading it to the shared OneNote. Marshall and Lucas would always be wanting to get straight into building, and I would always be flicking back to the research to see if it reflects on our building.

If we knew that we weren’t going to be there for a certain lesson, we would always email or message the group prior. After the day had finished, we would message on the group-chat to catch-up the work we completed in class.

Having all of your good friend’s in one group maybe wasn’t the best decision, and at times it showed that we shouldn’t all be in a group together, but also at times it showed that because we were all good friends, we knew each others strengths and weaknesses, so we were able to elaborate on that.

Conclusion

This whole task really helped me learn to what goes into designing an earthquake-resistant building and how much time, effort and pain people had to go through. I also learned from the engineering process and how engineers, scientist, and urban planners can use this very useful process to help them. Furthermore, this being a group task, I was able to show that I can lead a team, by helping my group members, staying organised, and giving constructive criticism.