Constructing Environments Journal W2

Construction Journal Submission Report Week Two: FRAME Nicole Tan 641433 Analysis of activity: Using 40 cut pieces of balsa wood strips, we were required to construct a tower as tall as possible whilst exploring the concept of frame construction. Frame construction juxtaposes week one’s concept of mass construction as the structure and enclosure systems in frame construction remain separate (Vassigh 2008).

Furthermore, by analysing the two construction challenges conducted, it is evident that frame construction is significantly lighter, more material efficient and quicker to build compared to mass construction.

The balsa wood strips had fairly low compression and tensile strengths due to its thinness (and hence smaller kern area). Therefore, we had to develop a construction system that reinforced and stabilised the frame to prevent buckling.

Furthermore, the weakest points in the construction system are the members and the joints which add an extra point for consideration with regards to joint construction and bracing.

Nicole Tan | Constructing Environments Journal

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Photographic sequence and description of the construction process: We chose to construct the base (and hence the tower) in a triangular shape as triangles are strong, rigid structures compared to their square counterparts. Furthermore, we utilised an overlapping/alternating pattern with the joints (see figure 1) to equalise the loads acting on each joint and member of the triangle.

Figure 1. Triangular base of each segment (Tan 2013)

Each segment of the tower simply joined two triangular bases using vertical columns at each of the three joints. Through this we created two triangular faces and three rectangular faces in each prism.

Creating a tower comprising of multiple segments allowed us to be time efficient and utilise a ‘production line’ system to construct the tower.

Figure 3. Bird’s eye view of the segment (Tan 2013)

Figure 2. Completed segment of the tower (Tan 2013)

The end product was 3 segments joined together with some additional diagonal bracing on the rectangular faces of the tower.

Figure 4. The tower comprising of multiple segments joined together (Tan 2013)

Nicole Tan | Constructing Environments Journal

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Analysis of construction system employed:

Figure 5. Sketch demonstrating effects of forces on a triangle and a square (Tan 2013)

We used a triangular base because of its rigidity. The shape can withstand a significant amount of force applied to its sides or corners without deforming the shape. This is because its rigid members are organised so that they are constantly fixed in the compressive and tensile limits of all its members (Fuchs 2012). This eliminates all possible forms of flexion.

A square however, as seen in Figure 5, is susceptible to flexion.

It can be transformed into a parallelogram if any force is applied to its corners.

Figure 6. Photo of fixed joint employed in the construction system (Tan 2013)

We constructed this joint so that the column is placed within the ‘pocket’ created by the triangle system’s joint.

This provided extra support and stability for the column as the triangle’s sides acted as strengthening mechanisms to assist in load transfer as well as reduce the effect of bending moments that joints are susceptible to.

Nicole Tan | Constructing Environments Journal

Figure 7. Photo of diagonal brace (Tan 2013).

The diagonal brace helped form a truss-like system where its members only experience axial tension or compression.

It helps strengthen the long columns and provide the rectangular face with the structural rigidity of a triangle (Ching 2008).

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Efficiency of material: The wooden balsa wood strips (if constructed properly with proper bracing) can withstand a fair amount of compression before buckling. In terms of material usage, this frame construction is much more material efficient than mass construction which indicates less waste produced to achieve the same result in height.

Sketches of deformation and stability:

Figure 8. Sketch of stable members (Tan 2013).

Figure 9. Annotated photo of deformation of the tower under compressive loads (Tan 2013).

Nicole Tan | Constructing Environments Journal

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REFERENCES Ching, F. 2008, Building Construction Illustrated, John Wiley and Sons, Hoboken, New Jersey.

Tan, N. 2013, Photographs from Constructing Studio Week 2, Melbourne.

Vassigh S. 2008, Interactive Structures-Visualising Structural Behaviour 2.0 (DVD-ROM), John Wiley and Sons.

Fuchs, J. 2012, Cleaning Technologies Group, New York, viewed 12th August 2013 < http://www.ctgclean.com>

Nicole Tan | Constructing Environments Journal

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