01_Ryan

A03: Studio Journal Constructing Environments

Ryan Zuzek

Ryan Zuzek

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Week 1: Compression

Task: Design and construct a block tower that is able to accommodate a live load.

Design We designed our tower with five different structural systems (Tetrahedron base, diagonal buttresses, semi-dome, fixed-end beams, and cylindrical body and spire) to ensure that the tower was equipped to deal with the gradually decreasing compressive force and increasing torsional force as the tower became more slender. As height increased, shearing force decreased we were able to focus on a slender spire to maximize height. This, as it turns out, critically sacrificed stability. The two processes we employed to ensure material efficiency were; spaced masonry, and decreasing tower circumference gradually as the tower grew. These four structural systems provided enough stability to accommodate the dead load of the tower itself. However, our focus on efficient material usage and increased application of dead loads rendered the tower body unable to cope with the torsional and/or lateral stress and it ultimately buckled.

Construction Stage 1: Tetrahedron base To account for the increased force at the base of the tower, we chose a wide based tetrahedron shape to distribute the force evenly along its three points. The base was reinforced with diagonal buttresses that aimed to increase loadbearing capacity and further distribute shearing stress.

Tetrahedron Load Path

Preliminary sketches

Finished plan

Tetrahedron base under construction

Ryan Zuzek

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Construction Stage 2: Tower body and semi-dome After establishing a strong base, we were able to change from a tetrahedral shape to a cylindrical body. This enabled us to construct a semi-dome to accommodate a live load (toy dog) and additionally enabled more efficient material usage. The semi-dome was chosen because it is effective at distributing collinear as well as nonconcurrent forces, equipped with a lower tension ring that contains the outward components of meridional forces (Ching 2008, 2.11, 2.26). The flooring system of the semi-dome used four fixed end beams to traverse the vacant horizontal space and was covered with a one-way system of blocks (See second from left) (Ching 2008, 2.15, 2.19).

Construction Stage 3: Spire The third stage of the tower, after creating the loadbearing foundations, was to extend the tower vertically. To maximize efficiency and minimize stress loads for the foundations, the circumference of the tower was gradually narrowed into a slender cylindrical spire. Narrowing the spire increased height and material efficiency yet this came at a cost to structural stability.

Tower body and semi-dome loadbearing paths

Tower body changing from tetrahedral to cylindrical

Semi-dome flooring system Semi-dome accommodating the live load

Semi-dome complete

Spire loadbearing path

Spire completed

Loadbearing path for the entire tower

Ryan Zuzek

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Deconstruction Stage After completing the tower, we tested to see if the structure was stable enough to bear a greater dead load. To test this we used a three plastic tubs and a cardboard box, stacked on top of each other. The structure maintained its integrity holding the first three tubs but due to construction flaws, was already bowing; a sign of torsional stress or lateral instability (Ching 2008, 2.13). By adding the boxes onto the spire, the stress load pinned the thinnest point of the tower causing the centre to deflect, as does a slender column when pinned by two forces (Ching 2008, 2.13). The more slender our tower became, and more stress it bore, brought it closer to the critical stress that

ultimately caused it to buckle.

The extra dead load added by the boxes pinned the slender tower body causing it to bend, and ultimately buckle.

Tower bearing three boxes as dead loads

Example of column bowing (Ching 2008, 2.13)

The point of critical stress, moments before the tower buckled

Game over.