Studio Report
Task: to use the least amount of timber blocks to build a tower as high as possible. The tower must accommodate a toy dog and have at least an open door.
Explore the efficiency of materials
Description and analysis of process In order to make a strong enough base to support the whole tower, we used masonry method in the most bottom four layers. The primary reason is that masonry construction allow loads to distribute equally throughout the structure. As depicted in the left sketch about the load path diagram of masonry structure base, we tried to keep two adjacent blocks occupying the same area on their nether block to make sure even compression force.
Firstly, think about the shape of the base, with the same length of radius of a space for accommodating toy dog, it is obvious that the round base uses less timber bricks than the square. Thus, we decided to make a circular base.
Secondly, as shown in the right picture, in order to achieve the goal of using the least blocks to build as high as possible, Type B is the most efficient. However, since the area of thrust surface is too small, Type B block will make the tower unstable. Thus, initially, we planned to use Type A at the bottom and Type C at the top to make sure enough area of thrust surface and try to make it relatively efficient.
The second reason is that masonry structure make structure very compressed. As shown in the red circle in the right photo, the blocks tightly keep together at the base. However, due to the circular base, there are some gaps between blocks externally. These gaps make the structure a bit loose.
After building four tight bottom layers, we changed the structure layout to the structure shown in the first photo. The reason is to use less blocks to get as high as possible. The left sketch shows the load path diagram of this part structure. Although this system carries many dead loads on the structure, it also creates more gaps which make the tower very unstable. Thus, as we build it increasing higher, we found we need to change the layout to previous masonry method to avoid the collapse caused by loose structure of massive gaps. The subsequent structure is depicted in the right photo.
As represented in the right photo, the circular design is suitable and useful for the task because we can build the bricks get increasingly closer on each layer and ultimately they will join together to become a roof to enclose the tower.
We decided to build the doorway during we constructed the tower. We wanted to design the arch like the first sketch above. Loads take the most direct route to the ground (Ching, 2014). In order to keep stability when building the arch, we explored that blocks should be added at the back to increase compression force, as shown in the second sketch above.
Deconstruction process The first photo below illustrates our actual constructing of the arch by applying the method I introduced on the previous page to make bricks from both sides get closer. However, the second photo below clearly shows that bricks have slope downwards to the left. This is because the added bricks as live loads take the shortest and easiest path to the ground which make forces tends to go down through the left air. Meanwhile, it is very difficult to add enough compression forces properly at the back during real building the structure as the tower goes high. Thus, when the increased forces at the left due to added bricks for building arch is larger than the loads provided at the back, the collapse occurred, as shown in the right photo.
Besides the reason of collapse mentioned above, the structure layout of the finished parts of the tower also contributes to the collapse. The top masonry structure is very dense but it nether framework is quite loose with many gaps. The added upper bricks become too heavy to be supported by the underneath. Hence, the tower collapses.
In order to test the stability of the construction, we took away some bricks at the base, as such as the place of the red circle in the photo above. We are able to remove some pieces because masonry method allows compression loads to transfer to other blocks. The load path diagram is shown as follow.
After that, we removed one brick from the place that is depicted in the red circle of the first photo below. the rest structure is still stable due to the compression force between other near blocks. Then, we removed its nether block, as shown at the blue circle, the column of the special structure fall collapsed while the main structure of the tower remained steady, as shown in the right photo below. As we continually removed one block at the place of black circle in the second photo, only the lateral column fell down. This proves that the masonry structure method indeed has perfect capability to deliver compression loads to others.
Comparison with other groups’ towers The left photo shows one group that used masonry method throughout the whole structure. Similar to our group, they also chose the circular base. Moreover, they achieved to get blocks increasingly closer on each layer and form an enclosed roof. Compared to us, they created a good door because they take away some blocks after finishing the whole tower. The place of red circle in the above photo it the critical collapse point of our structure. This is because it had point load. Due to the lack of support for the dense masonry at the top, there was too much load going through one point. The load was no more evenly distributed and it sought the most direct route to the ground. Thus, the whole structure collapsed.
Similar to us, another group also decided to use the circular base and create an arch during the constructing of the tower. However, since they have a very dense and tight structure layout, they successfully to finish the arch and the whole tower.
Learning Loop
This week’s pre-Learning mainly introduced loads and forces, construction overview, material introduction and Melbourne bluestone.
The load path diagram above depicts the load takes the most direct route to the ground. According to Newton’s Third Law, the load that passes through the structure will ultimately encounter a reaction force which is equal in magnitude and opposite in direction of the load (ENVS10003, 2014). Basic structural forces
Tension: move apart to stretch and elongate the material The determinants of elongation includes: magnitude, stiffness and cross sectional area (ENVS10003, 2014)
Compression: mover closer to shorten the material (ENVS10003, 2914)
Material introduction: (ENVS10003, 2014) 1.Strength:steel＞concrete＞timber 2.Stiffness:steel＞concrete＞timber＞rubber 3.Shape:linear/mono-dimensional, planar/bi-dimensional, volumetric/tridimensional (brick & concrete) 4.Material behaviours: isotropic (steel & brick), anisotropic (crystal) 5.economy:price, availability, transportation etc. 6.sustainability: e.g.: In Australia, timber is very sustain and available Melbourne bluestone: (ENVS10003, 2014) Bluestone( basalts) belongs to igneous rocks from volcano lava flows. Landscape is the fundamental background of the constructed city. The natural environment shapes the cultural environment. Melbourne is adjacent to volcanoes so bluestone is the main building materials of Melbourne. The bubbles of the surface of bluestone indicates Victoria volcanic lava past. P.S.: Sydney: sandstone Perth: clay of bricks, limestone Construction overview: (ENVS10003, 2014) The subject is mainly about how design ideas translate into the build forms. We should build the relationship of structure system and material chosen work. The choices of materials differ from place to place. The buildings ultimately become coherent architecture
Main types of Loads: (Ching, 2014) 1.Static loads: live loads, occupancy loads, snow loads, rain loads and impact loads 2.Dynamic loads: wind loads and earthquake loads
By hands-on building tower with using timber bricks in the studio, I clearly realised the brick belongs to isotropic material, added bricks are live loads, the advantages of masonry method which are quite dense and stable, most effective in compression and can deliver the load evenly through the whole structure and the importance of compression force in solid mass construction. I applied the load path diagram to analyse the forces of different structure in diverse stages of the process.
Glossary • •
Force: any impact which results in the change of shape and movement. It is a vector quantity with both magnitude and direction (Ching, 2014). Tension: stretch the material when an external load pull on a structural member (ENVS10003, 2014).
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Compression: material’s particles compact together after an external load pushes on a structural member (ENVS10003, 2014).
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Load path: the path that force transfers through the most direct route towards to the ground (Ching, 2014).
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Masonry: a form of construction which is generally made from clays (Ching, 2014). E.g.: bricks and concrete
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Point load: a load that acts at a particular point of a supporting structural element (Ching, 2014). Beam: transfers or carries loads across a span to the axial support columns (Ching, 2014). Isotropic material: It has similar characteristics no mater the applied forces in which direction (ENVS10003, 2014). Anisotropic material: it has inequality in compression and tension (ENVS10003, 2014).
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References Ching, F. D. K. (2014). Building Construction Illustrated (Fourth ed.). Hoboken, New Jersey: John Wiley& Sons, Inc. ENVS (Producer). (2014, 6/8/14).W01 Basic Structural Forces (1). Retrieved from: http://app.lms.unimelb.edu.au/bbcswebdav/courses/ENVS10003_2014_SM1/WEEK%2001/Basic%20Structural%20Forces%201.pdf ENVS (Producer). (2014, 6/8/14).W01 c1 Construction Overview. Retrieved from: https://www.youtube.com/watch?v=lHqrPyAphw&feature=youtu.be ENVS (Producer). (2014, 6/8/14).W01 m1 Introduction to Materials. Retrieved from: https://www.youtube.com/watch?v=s4CJ8o_lJbg&feature=youtu.be ENVS (Producer). (2014, 6/8/14).W01 Melbourne Bluestone. Retrieved from: https://www. outube.comy/watch?v=CGMA71_3H6o&feature=youtu.be ENVS (Producer). (2014, 6/8/14).W01 s1 Load Path Diagrams. Retrieved from: https://www.youtube.com/watch?v=y__V15j3IX4&feature=youtu.be