Constructing Environments Logbook Samantha McNeil 640122
Contents Page 1. Title 2. Contents 3. Week1 4. Week 1 Studio Activity 7. Loads 8. Forces 9. Looking At a Structure 10. Week 2 11. Week 2 Studio Activity 13. Soils & Topography 14. Structural Systems 15. Construction Systems 16. Common ESD Strategies 17. Environmentally Sustainable Design 18. Structural Joints 19. Week 3 20. Week 3 Studio Activity 25. Structural Elements 26. Role of Foundations 27. Footings & Foundations 28. Introduction of Materials 29. Properties of Materials
30. Clay Bricks 31. Concrete Blocks 32. Stone 33. Week 4 34. Week 4 Studio Activity 36. Floor & Framing Systems 37. Concrete 38. Concrete Process 39. Columns & Beams 40. In Situ Concrete 41. Pre – cast Concrete 42. Week 5 43. Week 5 Studio Activity 44. Wood To Timber 45. Timber 46. Engineered Timber 47. Beams 48. Week 6 49. Studio Activity 51. Roofing systems 52. Roof Systems 53. Introduction to Metals
54. Ferrous Metals 55. Non – Ferrous 56. Week 7 57. Detailing for Heat & Moisture 58. Rubber 59. Plastics 60. Paints 61. Week 8 62. Studio Activity 64. Glass 65. Openings 66. Week 9 67. Construction Detailing 68. Composite Materials 69. Week 10 70. Lateral Supports, Collapses & Failures 71. Heroes & Culprits 72. Glossary 81. Referencing
Week 1 Studio Activity
Loads Forces Looking At A Structure
Building The Wall The circular structure was proving effective structurally and in terms of efficiency as unnecessary corner spaces were eliminated – the goal was for height and adequate space. The gaps in the blocks could work as insulation and allowing breezes through the structure. The structural system is exposed which eliminates unnecessary material for the enclosure system (Newton, 2014)
Circular Frame The structural system (Ching, 2008) will be volumetric (Newton, 2014) as the material imitates bricks. The circular shape is used to minimise material use and to maximise height. The doorway has been left as a space, measured large enough to fit our object (toy horse), to be factored in later. The circular frame will allow a dome – like closure at the top to act as a ceiling. Load Path
R R R Strength Of Material Timber retains strength in compression and is a stiff material. Due to thick, short, rectangular shape the material will not buckle and will retain its shape under compression. The blocks at the base of structure were placed in a rotating orientation level-‐ by-‐level; first horizontally, then vertically. The horizontal placement dispersed the load over a wider area and provided stability, a system imitating the structure of a human foot (Newton, 2014). Vertical placement gave the structure height.
Closing The Doorway The problem was that the self – load of the overhanging blocks needed to be stabilised. Building up the sides of the structure, thereby transferring the load path horizontally and then vertically did this. The orientation of bricks imitates the idea of a Herringbone Pattern (Mitcheltree, 2014), getting the bricks to be self-‐supporting and locked as no structural connections or joints were to be used.
Structural Process At Height Once our height was above usable interior space, we minimised the structures circumference, as it would be economically unfeasible to continue to use so many blocks. Reducing circumference length dramatically decreased the number of blocks per level. As is shown in below photograph, each level contained four blocks once the ceiling was closed. While we could have built the tower with one block per level, this would not have been stable, and would have easily tipped. Ensuring the structure was stable maximised efficiency and minimized materials as it would last for a longer period of time.
Closing Ceiling Why? – Economically feasible. Similar to the process of closing the doorway, we let half the blocks over hang into the centre so that the self – load was still supported. Using only horizontally orientation of blocks maximised over hang and transferred the load path vertically. We built the structure to a close, ensuring load path was transferred through exterior blocks to the ground and then focused on height.
Comparison With Others This group used a square shape base, perhaps as it is the norm for houses in Melbourne. Using the interlocking idea of the Herringbone Pattern (Mitcheltree, 2014), the walls were sufficiently stable. On the left wall it is evident they replicated a double brick structure which would have been economically and environmentally efficient. It moderate temperature change and reduce the use of air-‐conditioning and heating.
Applied Loads Why did this structure stay up? Site conditions were controlled and stable: No wind, flat, and a strong building surface. Brunelleschi’s Ospedale degli Innocenti extensively uses columns as a part of the structural system (Selenitsch, 2014). Using precedent, we understand that the column structure transfers loads effectively downward and can sustain substantial point & uniformly distributed loads (Newton, 2014). In this instance it is uniformly distributed across the surface of the column. The Herringbone Pattern and strength of material combined with the structure supported loads greater than the weight of itself.
Critical Point of Collapse In the similar way that the doorway’s load path could be distributed horizontally and then vertically to the ground, we were able to create gaps in the structure before collapse. An example is shown in the photograph below. The critical point of collapse identified was in the middle of the structure when one too many a block was removed and an imbalance created. The self-‐load of the top of the structure became too heavy to sustain. The imbalance of weight caused the structure to tip. The dynamic force (Ching, 2008) of the falling blocks was not accounted for in the structural system and the structure collapsed.
Week 2 Studio Activity Soils & Topography Structural Systems Construction Systems Common ESD Strategies Environmentally Sustainable Design Structural Joints
Plan We intended to emulate a truss system inspired by a crane to create stability and strength in the thin balsa wood (Newton, 2014). Creating a triangular shape to cross diagonally down the sides of the structure would distribute the load and give the structure strength. We will create a brace to hold the posts together and stiffen the structure as is shown in the diagram below.
Efficiency of Material Anisotropic material (Newton, 2014) as the magnitude is easily distorted when a load is applied. Balsa Wood, a type of timber, is notorious for it’s light, breakable qualities. When in planar form it is a stiff material but can easily snap. Distributing the load through various load paths is the only option for retaining point or uniformly distributed loads in this structure. Creating a tower with timber is inefficient, as it tends to bend under compression.
Load Path Diagram
Construction System Employed It is a structural system as it is built above ground, and the structure held itself upright. True to a skeletal system the aim is to transfer loads to the ground (Newton, 2014). Where the truss system was used the structure was strengthened as two routes to the ground consistently divided the load. On one side we used fixed joints to vertically place strips of timber and this side was the first to show deformation when even a light compression load was applied.
Load Path Diagram
Structural Joints and Comparison Referring to the joints mentioned by Newton (2014), we employed fixed joints in our structure. Limited materials eliminated roller joints, and pin joints did not seem as effective although they are commonly used in construction. As a result of the fixed joint, bending did occur as deflection did not occur at the joint (Newton, 2014). However, using a fixed joint stabilised our structural joints. This group’s structure used pin joints. The flexibility of material is demonstrated by its 45° angle when point load compression applied. Shortly after deflection the pin joints gave way and the structure collapsed demonstrating the weakness of structural joints. The height of this tower was too great for the weakness of materials, and it was created on a slight angle, which caused an imbalance and inability to support its self – load.
Deformation Although balsa wood is quite a stiff, rigid material, it proved to be quite flexible when fixed into lengthy ties with fixed joints. The super glue and masking tape was very efficient in holding the joints together. Structural joints are generally a point of weakness as was seen in the other groups frame (Newton, 2014), however in the end it was the longer, weaker parts of the balsa wood that gave in first when compression was applied.
Published on May 18, 2014