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Edward Kwan-Shuen Yee 699508 ENVS10003 Constructing Environments Logbook
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Content
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Week 1 (Introduction to Construction)…………....……………..3~7 Week 2 (Structural Loads and Forces)................………………8~11
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Week 1
Tension & Compression
Intro to Construction Load Path Diagrams
Forces & Load
Tension & Compression‌ -Materials undergo tension and compression -Different objects have different properties that allow them to resist either tension or compression or both.
Forces & Load -Forces are a vector quantity possessing both direction and magnitude. (Ching. F.D.K, 2008) -Compression & tension happen when force is applied to an object.
Bricks resist compression very well.
Force is acting to the right. Force is acting to the left.
[Rands (2009, March 23), The Makers of Things. Retrieved from http://randsinrepose.com/archives /the-makers-of-things/] Steel wires resist incredible tension, making it capable to support a very heavy bridge.
Despite force moving to left, rotational movement is created.
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Load Path Diagram
Live load. Moves and adds/detracts weight to structure. =D Force finds its way to the ground. Dead load. Doesn’t move and weight is always exerted on structure. XO
Newton’s 3rd law. Every force has an opposite and equal reaction. If not, the structure would sink into the ground.
Diagram drawn by Edward Yee.
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Block Tower Project! We were asked to make a tower out of wooden blocks as high as possible. The results… Interlocking bricks resist compression exerted on bricks in all directions more efficiently.
An arch, the unique shape which only experiences compression.
Fat dinosaur goes through…
In an arch, weight of overhanging bridge would cause inward collapse before completion of arch. Hence, a cantilever is used. Another brick overhanging on opposite side will cause an anticlockwise moment to counteract clockwise moment of ‘collapsing’ arch. This is seen used in the brick tower building project.
Because bricks resist compression so well, they hold the weight of the structure without collapsing even though several bricks are removed to form an opening from a completed tower. Nicholas James Johan, 20/03/2014, Constructing Environments Studio 1
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In the lecture, we were given a piece of paper that we were to fold so as to support a brick.
So…how was it done with such a flimsy piece of paper?
In flat piece of paper, load travels perpendicularly down the paper. And because paper has terrible resistance to compression, it almost immediately crumples.
Load
In corrugated piece of paper: -the ridges formed from corrugation stiffen paper. -creased area becomes more resistant to compression. -centre of gravity is within corrugated structure unlike a single piece of paper
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Glossary
Load path: The ‘path’ that the load takes within a structure to reach the ground Masonry: Usage of stonework as construction materials Compression: the force that tries to squeeze a material Reaction Forces: a force that always exists in pair with action force, and is equal in magnitude and opposite in direction to it Point Load: a point where a bearing or structural weight is intense and transferred to the foundation Beam: rigid structural members designed to carry and transfer transverse loads across space to supporting elements
Reference: 1. Reaction Force (2013, 21 January), Retrieved from http://physicshomeworkhelp.blog.com/2013/01/21/reaction-force/ 2. What is a Definition of A Compression Force?, Retrieved from http://www.ask.com/question/what-is-a-compressive-force 3. What is a Point Load?, Retrieved from http://www.ask.com/question/what-is-apoint-load 4. Newton. C (2014, 5 March), W01 s1 Load Path Diagrams, Retrieved from http://youtu.be/y__V15j3IX4 5. Ching, F.D.K (2008). Structural Forces, Building Construction Illustrated, 4th Edition, pg2.11 6. Ching, F.D.K (2008). Structural Forces, Building Construction Illustrated, 4th Edition, pg2.14
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Week 2
Solid Systems
Frame/Skeletal Systems
Structural Systems Shell/Surface Systems
Membrane Systems
Hybrid Systems
Structural Joints: -Only takes load acting downwards. -Does not prevent horizontal movement (left/right)
-Takes loads and forces in all directions. -Difficult for engineers to calculate.
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In this week’s constructing studio, we got our cut pieces of balsa wood to build a frame tower as high as possible. Initial plans were to build a pyramidal tower with bracings at different levels and intervals to support. The end result however, was quite different. Initially, we wanted to glue our balsa pieces together. However, lack of time led one of our members to come up with a brilliant solution. Instead, we cut a small gap at the ends of the wood to create a forked wedge which we then later linked together. It resulted in a very efficient structural fixed joint (Newton. C, 2014) that resisted movement in all directions without help of glue.
Photo by Nicholas James Johan (2014, 14 March)
Photo by Nicholas James Johan (2014, 14 March)
-More bracings needed to be added towards to bottom as weight and load concentrated there. -Fixed joints at each bracings experienced mostly tension force as legs try to buckle/splay apart.
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The finished product. Some observations: -Due to bending of balsa wood columns, structure’s centre of gravity began to shift outwards -Possible toppling if structure went any higher. Stability compromised. -Solution would be to add more bracings to hold balsa wood beams in place and keep centre of gravity within structure.
Photo by Nicholas James Johan (2014, 14 March)
Another group’s tower was also observed: -Also a pyramidal base configuration. However legs crossed each other midway. Acts as a fixed joint. (Clare Newton, 2014) -Bracings holds legs in place like our tower and prevents legs from splaying apart.
Photo by Clarybelle Loi (2014, 14 March) Photo by Nicholas James Johan (2014, 14 March)
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Glossary
Structural Joint: the place at which two things, or separate parts of one thing, are joined or united, either rigidly or in such a way as to permit motion Stability: firmness in position Tension: the state of being stretched or strained Bracing: something that holds parts together or in place, as a clasp or clamp Frame: a rigid structure formed of relatively slender pieces, joined so as to surround sizable empty spaces or non-structural panels, and generally used as a major support in building or engineering works, machinery, furniture, etc Column: a rigid, relatively slender, upright support, composed of relatively few pieces
References: 1. Newton. C (2014, 9 March), W02 s1 Structural Systems, Retrieved from http://youtu.be/l--JtPpI8uw 2. Newton. C (2014, 9 March), W02 s2 Structural Joints, Retrieved from http://youtu.be/kxRdY0jSoJo 3. Dictionary.com, Retrieved from dictionary.reference.com