CONSTRUCTING ENVIRONMENTS -‐ LOG BOOK
Gabriella Bertazzo STUDENT #: 698897
I N T E R M S U B M I S S I O N 2 1 / 3 / 1 4
GLOSSARY
Week 1 Key criteria of materials _____________________________________________pp.3 Types of loads _____________________________________________pp.4 Mass activity ____________________________________________pp.5-‐8 Week 2 Structural Systems _____________________________________________pp. 9 Construction systems ____________________________________________pp. 10 ESD ____________________________________________pp. 11 Structural joints ____________________________________________pp. 12 Types of systems ____________________________________________pp.13 Structural systems activity _____________________________________pp.14-‐18 Terms ___________________________________________pp. 19 Reference list ___________________________________________pp. 20
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LOG BOOK Week 1 -‐ 3/3/14 v Introduction to construction eLearning Key elements of the subject: • How do design ideas get translated into the built environment? • The efficiently of structures and materials • The differences form city to city, climate to climate • Construction as a paradox for complexity, simple and coherent. Key criteria of materials: - Strength à some materials react differently to compression and tension Eg) steel – strong material against both compression and tension Brick – strong material against compression only - Stiffnessà referring to the flexibility of a material Eg) nylon rope – highly flexible Vs brick – rigid/stiff - Shape à 3 types Mono-‐dimensional (linear) Bi-‐ dimensional (planar) – eg) sheet metal Tri-‐ dimensional (volumetric) – eg) brick - Material behavior à 2 types Isotropic – similar characteristics no matter which direction the force is applied (Newton, 2014) Anisotropic – equally strong in compression and tension - Economy/ sustainablyà relation to the environment/economy and how it is effected. Factors needing to be considered: - How readily available - Cost - The impact the manufacturing of the material has on the environment - Transportation and distance - Efficiency of the material in the construction process Case study 1 à ‘Walking the Constructed City” (blue stone) Theme: ‘How Melbourne’s natural environment has effected its cultural environment.’(Grose,2014) Darkness of the bluestone becomes and identifier for Melbourne. Eg) Melbourne is represented as dark whereas Sydney is represented as lighter due to the sandstone used throughout the city. Bluestone as an indictor of the past: evidence of horse and carriage, types of construction methods( rougher bluestone bellow the surface), impacts of water and erosion.
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Adaption: blue stones strong structure is now used as the foundation of buildings. Eg) cathedral The Building Types of loads: • Static loadsà applied slowly • Dynamic loadsà applied suddenly to the structure • Wind loads – kinetic energy in a horizontal direction with negative pressure. Involves flutter. (Ching, 2008) • Earthquake load -‐ longitudinal/transversal vibrations (Ching, 2008) Base shear is distributed to each horizontal structure equally to achieve equilibrium. Tutorial v Compression and response to force Loadsà the most direction route to the ground. To be stable there is a equal and opposite reaction against the load. Types of loads: Point loadà concentrated on one point Uniform load à equally distributed through the entire structure Live loadà not permanently part of the structure Dead load à part of the structure system Impact loadà kinetic energy of a small period Settlement loadà sinking of supporting soil = differential settlement of foundations (Ching, 2008)
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Diagram: Directionality
Tutorial activity MASS ACTIVITY Aim: To construct the tallest structure using MDF blocks. Restrictions: Amount of blocks, time, must have opening to fit size of horse. Type of system: Relatively even circular structure through a weaved effect. The process consisted of evenly stacking the blocks to produce a consistency throughout the whole structure. As a group our aim was to appropriate the system of Janga. Efficiency of materials: Due to the MDF pieces been uniform the material was easily adapted into a structure because there was no concern in different weights and sizes. The process: Cut the sheet of paper to represent the size of the horse. First several layers were closely stacked to ensure strong foundations and a proportional circle. Problem: we became aware that we needed to create a doorway. Solution: adjusted the sides of the structure that would be a stronger support for the doorframe. By placing the blocks closer together it allowed us to create a kind of bridge, where the blocks balanced out each other to avoid a collapse. 5
After the doorframe was completed we reverted back to the original system of weaving the blocks to provide consistency to the structure. Taller and thinner structures have greater force applied through the same load path. Meaning greater opportunity for collapse
Problem: We were running out of time, blocks and another groups tower was increasing in height rapidly. We couldn’t decide on an efficient method of increasing the towers height. Placing the blocks vertical was unstable and there we no further direction once they were stacked. Solution: We borrowed the idea from another group to alternate in block rotation. However we didn’t believe that that type of system was sturdy enough so we reverted back to the original way. Final design included two types of systems. The Janga type system and side stack system. The incorporation of the two allowed to structure to compensate for different load types, as the weight was distributed evenly. By having the door small and close to the ground, this meant the strength of the building increased and building upwards wasn’t affected. 6
Point load: Once completed we were able to stack 3 loads of MDF buckets onto the structure. Roughly about 30kg weighted on the system. Due to safety reason we were unable to continue loading onto the tower however the evident sturdiness and strength of to tower the possibility of more boxes could have been added.
Change of load: We gradually pulled away part of the structure to establish the collapse point of the system. Surprisingly the structure was able to remain stable for quite some time before collapsing. In theory this is because valid load paths were still available and able to support the remaining system.
Other Groups structures: Same sort of system as our however the shape is consistent, meaning there wasn’t as much strength and support. Used the stacking system throughout the entire building, which creates certain strength within the system. This group achieved the highest building through the initiative of decrease the diameter of their circle closer to the top. This meant the height increased at a quicker pace and fewer blocks were being used.
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This group worked on building strong foundation as seen with the several types of methods used. The reason why the structure is so short is because they focused on strength rather than height. The double walls and size of the base meant more blocks had to be used, this decreasing the height of the building. What worked: the weaving system created a strong structure. Also the use of a circular structure provided an even building that could withstand the point load of the boxes.
What could be done better? - When pulling part of the structure out, the point of collapse was the doorway. The plan for the doorway could be better conceived and structured, as we didn’t build in a set way, we just made our own way up. This therefore created instability. - To satisfy the brief of building the tallest tower, we could have created a smaller diameter or gradually built inwards in order to achieve a greater height. However this may have affected the stability of the tower. Red: outer system had clear load path direct Uneven system, to t he g round some blocks not even p roviding a load path CONCLUSION: The use of a compressive load allowed the circular structure to evenly transfer the self load to the ground, creating a much stronger system. This was evident when our structure was loaded up with large boxes of material. It is evident that the weaved system efficiently was able to distributed the point load.
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Week 2 -‐ 12/3/14 v Structural systems
(Newton, 2014)
(Newton, 2014)
Solid systems – compression action Eg) the pyramids or masonry bridges Surface/shell systems-‐ usually composite but forms one material. 1-‐2 ways of curvature. Eg) Sydney opera house Skeletal/frame systems-‐ clear indication of form. Clear example is timber frames for residential housing. Eg) Eiffel tower Membrane system-‐ umatic structures, reinforced by tension Eg) sails Hybrid systems-‐ working in unison, meaning it cannot work without the other components
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Environmentally sustainable design + selecting materials - Directionality
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(Linden, 2012)
Green building strategies Embodied energyà total energy used LCA of materials Cradle to cradle o Recyclability: available technology, facilities, education o Shorter travel, time, $$ enhances recycling Materials selection à eg) concrete is not recyclable however can be reused for aggregate à New trends
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EXAMPLE: Council House 2 Use of local materials, material efficiency, night air purging, smart sun design, passive strategy of heating and cooling. EXAMPLE: Wood Positive carbon footprint, must be replaced = neutral carbon footprint Absorbs + stores C02 ! compensates for energy used in production Constantly been reused
(European Panel Foundation, 2014) Structural joints
Roller joints – loads transferred in one direction. (Horizontal) Must allow for movement to avoid strain on structure. Eg) bridges Pin joints-‐ within a truss system. (Newton, 2014) Loads/ actions can be from two or more directions. (Horizontal and vertical) Eg) used in buildings Fixed joints-‐ resists any movement Eg) steel frames 12
Differences in joints Types of systems 1. Structural Supports lateral loads. The superstructure in a vertical extension from the foundation (Ching, 2014) Columns/beams support roofs and flooring and substructure is the underlying foundations. 2. Enclosure system Roof and walls shelter interior from moisture, heat etc. but also dampens noise provides security. 3. Mechanical systems Provide essentials for the building to function - Water supply, sewage disposal, heating/ventilation Lecture: How much force a single material can take. Outcome been that a cylinder that is vertical can hold a more substantial amount of weight than a cylinder that is on an angle. Direct force is applied h owever the Direct route route is compromised by the angle downwards, to the cylinder. The oppositional with equal fore is uneven with the applied force oppositional causing a collapse. force =equilibrium 13
Tutorial How to accommodate lateral loads Activity: Structural systems Aim: To construct the tallest structural tower using 20 balsa wood strips. Considering joining systems to produce the strongest frame. Material: Balsa wood is a soft, flexible material. At stress points can break easily however when re-‐enforced correctly can become strong. Initial ideas: 1. Problems: not enough material to build with so the structure was self standing 2. Strong frame however again to create four sides with the amount of materials the height of the structure would not have been there. 3. Development of the triangular form and height. However knowing that balsa wood isn’t that strong. One piece by itself would not hold any weight. 4. Incorporation of 2 triangles. The base having structure and the top providing a flat surface for any point loads, however the center is a clear point of collapse, as the top triangle is only supported at one small point.
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Problems faced: As a team communication lacked so a clear design idea was not fully conceptualized prior to construction. This meant there was no clear direction of how or what we were building. This created several problems when trying to choose support systems and structural shape. In the end it came down to trial and error. Process: The use of tape to hold the materials together better than pins. Tape been used to represent a fixed joint, therefore allowing no movement. Use of triangle to create the basis for a pyramid structure. To provide stability we inserted the vertical pieces on the inside of the triangle. This created a point of contact with the foundation allowing it to hold the vertical in compression. To ensure the recent add on were supported we attached horizontal pieces around the triangle. To create height we connected the strips together by overlapping a centimeter for greater strength. Another triangle in the centre was added to provide stability to the new joints on the tall verticals pieces. How we made the joint stronger and why? 15
Problem: we discovered that the vertical sidepieces we separate to the foundation, meaning the strong foundation we had created were doing nothing to support the actual structure. Solution: used connecting pieces to join both structures together. A last triangle was added to the top of the frame to create a flat space for a load. Testing of collapse points: What: Force was slowly added to the structure to determine the weak points/joints of the system. This showed us the errors in the frame and to demonstrate the importance of good structural system and the correct type of joint method. Slowed motion of collapse:
First point of weakness: The free standing verticals with no triangular support.
Second point of weakness: Small connectors to the outer structure. This is because that are slanted and more inclined to be affected by compression.
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Load path for structure:
Third point of weakness: One of the outer vertical pieces has completed detached itself from the structure. This is because we used the pin joint, so the structure is then able to rotate. a solution to this would be to have used tape; acting as a fixed joint. This allowing no movement.
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What could be improved? Communication -‐ A clear design idea before construction. This allows everyone in the team to understand the common goal also allowing time to be used effectively. The structure-‐ More supporting pieces to outer vertices. This creating overall stability to the structure. Consideration to the type of joint that best fits the desired function. This will ensure the movement of the building is compensated for in the correct areas. What worked well? The foundation shape created strong base for the other elements to connect to. By using triangles its helps to support the structure. The places where these we present withstood the load for a longer period of time than the places without them. CONCLUSION: when force is applied to a structure, the points of weakness are what cause collapse. This may be due to incorrect use of materials, joints and structural systems. In our frame the overall frame was conventional however we used the joints in the wrong places, this causing tension on the joints and inevitably collapse. 18
TERMS
Week 1 Load paths à most direct route of force to the ground. Achieved through equal and opposite reaction. Masonry à building structures made from individual units that are bound together. Eg) mortar Compression à application of balanced inward forces to different points on a material. (Collins English Dictionary.2009) Reaction force à the opposite amount of force that reacts to an applied force. Point load à temporary part of the structure concentrated on one point. (Newton, 2014) Beam à sturdy, long metal or wood used as foundational support in a building. (Google, 2014) EXTRA TERMS Flutterà rapid oscillation of membrane structure. (Ching, 2008, pp. 2.09) Tall and slender building subject to it. Base shear à minimal design value Equilibrium à achieving a balance through external restoring moment or internal resisting moment. (Ching, 2008, pp. 2.08) Week 2 Structural joint à how building structures bind together. Stability à resistance to change, deterioration and displacement (Wifflin, 2009) Tension à pulling force exerted by a solid object Frame à rigid structure surrounding something Bracing à serving as a brace to a structure as a kind of support system Column à upright pillar supporting an arch or other structure. Or standing alone as a monument. 19
Reference List Ching, F. (2008) Building construction illustrated. (4). (chap.2),(pp.2.02-‐2.03) United states: John Wiley &sons ,Inc. Ching, F. (2008) Building construction illustrated. (4). (chap.2 ),(pp.2.08-‐2.11) United states: John Wiley &sons ,Inc. Collins English Dictionary. (2009). Compression. Urban Dictionary. March 21, 2014. Retrieved from http://dictionary.reference.com/browse/compression?s=t European Panel Foundation. (2014) The carbon cycle of timber and wood based products. [photo illustrated]. http://www.timber.net.au/index.php/environmental-‐ design-‐carbon-‐footprint.html Google. (2014). Beam. Define: Beam. March 21, 2014. Retrieved from https://www.google.com.au/search?client=safari&rls=en&q=define:+beam&ie=UTF-‐ 8&oe=UTF-‐8&gws_rd=cr&ei=MvYqU4b0McWNkwXZ1IGQCQ Grose. M.[The University of Melbourne]. (2014, March,6). Melbourne’s Bluestone “Walking The Constructed City”. https://www.youtube.com/watch?v=CGMA71_3H6o&feature=youtu.be Linden, J.E. (2012) 15 Mojave River ranger Station -‐ Sustainable diagram. [architectural diagram]. http://www10.aeccafe.com/blogs/arch-‐ showcase/2012/10/25/mojave-‐rivers-‐ranger-‐station-‐in-‐acton-‐california-‐by-‐marcy-‐ wong-‐donn-‐logan-‐architects/15-‐mojave-‐rivers-‐ranger-‐station-‐sustainable-‐diagram-‐ section/ Newton, C. (2014) Structural systems. [illustrated image]. http://www.youtube.com/watch?v=l-‐-‐JtPpI8uw&feature=youtu.be Newton, C. [ ENVS10003]. (2014, March, 5). W01 m1 Introduction to materials. (YouTube). http://www.youtube.com/watch?v=s4CJ8o_lJbg&feature=youtu.be Newton, C. [ENVS10003].(2014, March, 9). W02 s2 Structural joints. [YouTube]. http://www.youtube.com/watch?v=kxRdY0jSoJo&feature=youtu.be Wiffilin.H. (2009). Stability. The Free Dictionary. March 21, 2014. http://www.thefreedictionary.com/stability
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