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Week one

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During the theatre session we looked at different shapes which are effective in bearing a point load (in this instance a brick) with a piece of paper. Some shapes I experimented with were triangles and columns. Both were successful in supporting the brick through compression force. Triangles are a strong shape and figure 6, below, demonstrates the relationship between the load and the triangular shape and how the compression and tension forces work together to support the weight of the load.Figure 5, shows how diagonal bracing can be used to add strength to a structure. I have observed triangles used often in various structures, for example Sydney Harbour Bridge.

Figure 1. Brick and columns 2014 Figure 2.Brick and columns 2014 Figure 3. Paper star 2014

Figure 4. Paper star and brick 2014

Figure 5. Diagonal brace 2014Figure 6. Triangle 2014 Figure 7. Columns 2014

Theatre session

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Figure 8. Loads 2014

Figure 9. Load transfer 2014

Loads

Figure 8. demonstrates the different types of loads.Static loads are applied slowly, with little fluctuation eg people/cars. These moveable loads are known as live loads. The building structure itself is a load, and is considered a dead load. It can also include fixtures and other elements in the building. A dynamic load is applied suddenly and rapidly, for example a tornado/strong winds.

I viewed Newton’s youtube video on load paths. Figure 9. demonstrates how a load is transferred to the ground. It is important to note it will take the most direct route to the ground, which is why some parts of the beams are not supporting or transferring the weight. (we will see this again on the following page with the tower built in the studio).At the ground level reaction force is occurring, which enables a stable structure. To create this stability the reaction must be equal and opposite to the force of the applied load.

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While constructing towers in the studio session we explored how loads can be transferred down through a building to the floor. By using a beam we were able to create an opening in our tower (see figure 10). As detailed in Figure 11, the beam has both compression and tension forces, which work together to allow the beam to support loads, in this case a static load.The material used was suitable to the task as it was strong yet light enough to allow for multiple stacking, which enabled us to build quickly to achieve height.

Figure 10. Beam 2014

Figure 11. Beam 2014

Figure 12. Deconstructing the tower. 2014

Figure 13. Tower 2014

Studio Session

We later attempted to remove some of the blocks from the tower which were not load bearing (see Figure 12). It was interesting to see the large amount we could remove before the tower collapsed. We removed almost one whole side before it fell down, which indicates the weight was not evenly distributed. While the weight of the load will take the most direct route to the ground, in a better planned structure you would expect the load bearing blocks to be more evenly spaced. Figure 13. shows clearly the completed, and slightly uneven tower.

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Materials

Figure 14. Former CUB 2014

Figure 15. Bluestone on Queen st 2014

As Dr Rose (2014) mentions in the elearning content, bluestone is commonly found in Melbourne buildings due to basalt being a readily available resource in Victoria. I observed figures 14 and 15 while walking through the CBD . When selecting materials for construction, the availability is important as choosing local resources impacts on our

economy and environment. Newton (2014) identifies the other key areas to consider when selecting materials are strength, stiffness, shape and how the material behaves. As I discover in the next studio, the type of material you use can have a big impact on your project.

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Week Two

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Theatre Session

Figure 16. triangle brace 2014 Figure 17. Columns supporting weight 2014

Figure 18. Columns collapsing 2014

During the second theatre session we explored how different shapes can add strength to building structures. Through the use of straws and pins (see figure 16) we attempted to support a heavy weight. Ching (2008) he discusses the importance of bracing to create stability. At home I recreated this experiment, and building on my knowledge from week one on the triangular shape, I attempted to create a brace between the straws for added strength. This was unsuccessful, however I suspect this had a lot to do with the materials (cheap plastic straw, than the technique itself). As you will see later in this log book entry, the use of bracing and triangular shapes for strength was quite successful during our studio session.I also experimented with columns, as the elearning content had reiterated the strength columns together can have. I cut the straws in quarters and attached them around the base of the container, and as you can see in figure 17, this was quite successful in holding an increasingly heavy weight. In figure 18, you can see there was a limit to how much weight the columns could hold, and my thick text book was far too heavy!

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Studio Session

Figure 19. Bracing to add strength 2014

Figure 20. Tower 2014

Figure 21. Good example of strong tower 2014

During the studio session we constructed towers from balsa wood using the knowledge we had gained regarding strong shapes, joints and materials. From Ching (2008) and the elearning modules. As the balsa wood is very flimsy we had to think of a way to over come this so we could increase the height in our tower without it toppling over. We used triangular shapes throughout the building process (figure 20) to provide support. We used fixed joints throughout the structure to aid with stability. However, our tower was not very strong and would not have held much weight at all. One key factor missing was a foundation, which would have added much more stability. To overcome this we could have built a wider base which would have provided more support.

Figures 19 and 21 show good examples of other students who have incorporated triangles throughout their structure for bracing. Figure 21 especially looks very strong, and far more stable than our tower (figure 20).

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Figure 22. Roller joint 2014 Figure 23. Pin joint 2014 Figure 24. Fixed joint 2014

Joints and Structures

Figure 25. Structural Systems 2014

KEY POINTS

Roller Joint: restricts up and down movement, but can still rotate and move side to side. – common in bridges

Pin Joint: restricts up and down, and side to side movement, but can still rotate. Very common, used in houses. (Good for when you only want a little movement)

Fixed Joint: there is no movement, and if used incorrectly can cause bending at the joint.

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Knowledge Map

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Structural Joint: roller, fixed and pin joints. See figures 22,23 and 24.Stability: Important element in building structures, can be provided at both substructure and superstructure levels. Frame: Part of the structural support system of a building. The surface/skeleton of a structure.Bracing: Additional support to a structure to make it more stable.Columns: structural members designed to support loads applied.

Load Path: See Figure 9.Compression: The force of two objects pushed together.Tension: The force of two objects being pulled/stretched. Eg trampoline.Reaction Force: Acts in opposite direction to action force. Equal in magnitude, opposite in direction.Point Load: A bearing weight is intense and transferred to the foundation.Beam: See Figure 11.

Glossary

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Reference List

Ching, F 2008, Building Constructed Illustrated, 4th Edition, John Wiley and sons, New Jersey

Groves, M 2014, Melbourne’s Bluestones, You Tube http://www.youtube.com/watch?v=CGMA71_3H6o&feature=youtu.be

Newton, C 2014, W01m1 Introduction to Materials, You Tubehttp://www.youtube.com/watch?v=s4CJ8o_lJbg&feature=youtu.be

Newton, C 2014, W01 s1 Load Path Diagrams, You Tubehttp://www.youtube.com/watch?v=y__V15j3IX4&feature=youtu.be