Part C [Detailed Design]Paulina Pytka637869Architectural Design Studio: AirTutorial 8

(Google Earth, 2015)

(Google Earth, 2015)

Neighbouring facilitiesPathsCycling tracksPlaygroundSchool

Bordering residential area

Choice of four trees from which to suspend the design in reference to sewer vent and users (families and cyclists)

Choice of siteThe location best promotes inter-action with the installation as it is bordered by pathways and tracks,

while being within close proximity to Merri Park and Northcote High

School

Situated in relation to topogra-phy, the design will interrupt the

natural descent prescribed by the downward slope towards Merri

Creek

The sharpest slope observed on site provides topographical varia-

tion and subsequently, variation in length and height parameters for the design’s underlying gridshell

algorithm to respond to.The

A group of stable, tick stumped trees were identified to support the

design in a relatively barren land-scape for the purpose of enhanc-

ing aesthetic intrigue of the site T

(Google Earth, 2015)

Organic/width

The on-site trees that would inform the shape of the design were represented as vertical lines on the base topographical geometry.

Between these lines, a series of curves were mapped to the topographical geometry. The organic series interpolat-ed a curve between three trees while the geometric series linked them with two straight lines.

The variation of this base geometry was explored by changing which trees were used and therefore the direction of the central divide; whether it cuts the result-ing plane along its length or its width.

It was necessary to obtain three curves for the application of the gridshell algo-rithm that would connect the specified boundaries through the “shortest route” method while referencing the line in the center.

Boundary

Geometric/width

Organic/length

Geometric/length

Organic/width

Offset

Offset

Offset

Offset

1

-1

-3

3

4

5

-4

-5

Division

5

Division

10

Division

20

A

Geometric/width

Offset

Offset

Offset

Offset

1

-3

3

-4

-5

4

5

Division

5

Division

10

Division

20

-1

B

Organic/length

Offset

Offset

Offset

Offset

1

-1

-3

3

4

5

-4

-5

Division Division Division

5 10 20

Geometric/length

Offset

Offset

Offset

Offset

1

-3

3

-4

-5

4

5

Division Division Division

-1

5 10 20

[A]

Organic/widthDivision 5Offset 4/-4 Despite the irregular boundary of the base geometry boundary, this outcome, after the applica-tion of the gridshell algorithm, has produced a relatively regular, structured frame.

An area of particular interest was the center that was left relatively open among the series of intersecting lines. This presented a suitable area for the draping of a material that could act as a well for sitting.

Additional areas were selected on the basis that they were connected to the central one only by their edges to create a pattern of solid and fluid elements within the gridshell frame.

The outcome is a suspended platform consisting of contrasting areas of hard and soft materials in correspondence to their use for either standing or sitting respectively.

EvaluationAlthough this design presents an opportunity for interaction with the environment through two different states of stiffness and relaxation, this is limited to the design itself without significantly referencing the site. In this way, a sense of place is partially lost. Perhaps the sitting wells would be better connected to the site if they corresponded to wells in the topography however this is not possible where there is little variation in the natural landscape.

Grasshopper mesh relaxation algorithm

[B]

Geometric/widthDivision 20

TrendAs the shortest distance arcs in this series run in the north south direction, perpendicular to the contours, the division of the width inside the boundary proves to be the most sensitive to variations in topography.

Accordingly the changing offset values reveal an area that is con-tinuously isolated as the gridshell algorithm works around it.

This area has been selected to be the focal point of the design of the sitting well.

Fixing to treesThis design is both physically and conceptually anchored to the four trees identified on site. Accordingly, in order to interact with the site selected for this project, the structure will be fixed to the trees, however, this will be done in a way that should have a limited impact on their growth. Perhaps this structure could be a seasonal installation for the warmer months that utilizes the trees’ coverage and shade when it is only deemed sufficient and suitable.

Brackets

In the case of a permanent installation. Fixed directly to the tree’s bark with bolts, a bracket will be overgrown by additional rings over time. Seasonal installation would mean screwing brackets into a tree repeatedly, potentially in different spots, damaging the bark and compro-mising structural stability as a support.

Slings

Tying the structure to the trees would be a more suitable method for repetitive reinstallation without damaging the tree. However, there are considerations for the ability of this method to bear the load of a large structure, effectively employing only the force of tension to maintain it in place. Although this may not affect the bark of the tree, it may cause it to buckle as a support.

Clamps

O-ring clamps have the benefit of being minimally invasive to tree bark while being able to be attached to a specific location along a tree’s length. This is the fixing method that will be most suitable for the temporary installation of the hammock project.

Fabrication

Digital fabrication

The benefit of considering to fabricate this design digitally is that it would maintain the precise geometries of

the gridshell definition as it responds to the site’s topography. However,

in order to achieve this, the tensile members would have to be rigid.

Manual fabrication

From case studies such as LAVA’s Green void installation, it is observed

that economical use of material is that brought into tension, to cover

the greatest distance with the least material. This can be used to extend

the gridshell concept of maximum definition of space with minimal

material use if tensile string members are used for the woven component of

the design.

In order to achieve the gridshell de-sign using string, one would have to

fabricate it manually and thus, simplify the way in which the boundary, or

frame, of the design will be joined by the tensile members. This means

limiting the “shortest paths” to two dimensions.

Another significant alteration, specific to the fabrication process is the use of the steepest slope area to dictate bending in the “shortest routes” as

opposed to the central division of the boundary frame explored earlier.

Eastern elevation of z-axis variation

Eastern elevation of key z-axis variation for manual fabrication

14.5m

0.48m

14.5m

0.25m

Plan with measurements of length and angles

7.83m

8.66m

8.18m

6.24m

104°

54°

141°

61 °

Prototyping

Each tensile member pulled through individ-ual corresponding hole through the thickness of the frame and secured by a simple knot on the outside

The fishing wire has a curvature of its own that comes across in the structure irrespective of the design informed by the site topography. Knots and densification of material have been used to create openings in reference to the site. They main opening responds to the highest point on site, omitted by the gridshell shortest path logic.

A thin, highly elastic mesh material was placed in the main opening of the tensile area of the design. This is the highest point on site that is avoided in the shortest route simula-tion of the gridshell algorithm that has been developed. By placing a sitting well here, the user is enabled to engage with the topog-raphy and take advantage of the viewing opportunities it offers.

[1]

Because the tensile members force the frame inwards, it is deformed and ultimately broken. The use of a stronger material may minimize breakage, however, in order to control the deformation of the frame, additional horizontal bracing within the frame should be considered.

Prototyping

[2]

A long piece of thin, perforated steel was bent into the shape of the frame and a wire string was run from one end to the other, through the openings, employ-ing the“shortest path” technique of the gridshell algorithm.

One long piece of wire was used for the entire project. This facilitated the fabrication process as it eliminated the need for tough cutting. Accordingly, this means less material waste associated with trimming. Only one pair of ends was secured with a swage as opposed to using many fastening devices.

The wire tensile members within the steel frame were observed to lock into place due to the coarse teeth of their spiraling fibers hooking on the edges of the holes of the frame. This was further supported by the wire’s outward thrust as it attempted to return to its original straight form.

Deformation of the outside steel frame was also observed however, as the material is stronger, it did not break. Perhaps having the perforations in the center on the steel is a disadvantage as this area should be reinforced as opposed to made weaker through the reduction of material.

Prototyping

[3]

A series of timber beams were believed to be the next suitable choice for the frame. These allowed for strict control of joints, in terms of how each corner comes together, while also allowing for drilling holes where necessary to secure the interior string complex. Adequate resistance to the subsequent tensile forces was also noted.

Steel bracing was used to fix the frame mem-bers together. They were originally right angle bracing that were hammered into a form that corresponded to the angle at a particular corner. An important observation for the final fabrication is that pre-drilling is essential for any screws going into timber as they may split it.

A hook and swage fastening technique was used to secure the metal wire in tension within the frame.

This prototype was particularly unsuccessful in matching up the frame’s angles, thus emphasizing the precision with which timber must be treated. The final out-come however, despite the gaps, is an accurate representation of the true angles of the frame that will be required on site.

Prototyping

Each timber frame member was divided into equal points that were pre-drilled before a small hook was screwed in the place.

Fishing wire was selected for the articulation of the string tension system within the frame. It required a specific uni knot to secure it into place as the conventional knot failed earlier in the prototyping phase.

As the hooks anchor the fishing wire are se-cured midway across the timber frame beams, additional bracing in this area was believed to be required to resist the inward tensile forces. Hence a t-section beam was selected.

[4]

Improvement in accuracy of timber frame joints.

Prototyping

[5]

Initially, the sitting well component of the design was cut from a very thin, flexible mesh fabric, however a thicker, more loosely woven material was sought for grater structural strength and aesthetic suitability to the greater design.

A burning technique was trialled to seal the edges of the material. This caused discoloura-tion as well as deformation. The alternative was the use of a hot glue gun that, despite producing some infill to the mesh, effectively secured it to the wire and sealed the edges while still allowing for flexibility within the structure.

A thin wire frame was made to govern the form of the mesh patch. A corrugated piece of wire allowed for it to grip to the material as it was passed through the loops in a weaving manner.

The mesh and frame are to be linked with no gaps to produce a uniform patch

Non uniform densification of ma-terial where it has been connected to the frame

Final detail model

Fishing wire brought into tension, skimming the steepest area on site, as it is omitted from the gridshell algorithm. This creates the space for the sitting well.

Conceptual, retractable access deck

Mesh sitting well frame secured to tensile system using thin wire ties

Final detail model

Final presentation

feedbackThe sitting well can accommodate

for one person, can this be justi-fied? Algorithmically, yes because

its location and size are dictated by the gridshell algorithm which omits this particular area due to

its steepeness that doesn’t match the “shortest route” method. There

is no other area on site like this and therefore another sitting well

cannot be made and justified.In this way, the design provides

a unique, individual experience of an isolated, uninterrupted axial view from the site to Merri Creek.

Choice of representational trees, whose foliage is made of semi opaque paper was believed to

create a particular ambiance, reflective of that experienced in

real life in sifting out light, particu-larly in summer when the design is meant to be installed. However,

the criticism of the trees’ lack of re-finement in relation to the design has made a case for their formal-

ization for the final submission.

Final submissionElements:

1. Frame: the frame was informed by the location and distance between the four trees on site. It consists of durable t-section timber beams joined at angles represen-tative of the direction from one tree to another and secured to the trees using o-ring clamps.

2. Tensile system: the tensile wire system inside the frame is the result of the manual application of the gridshell “shortest route” prin-ciple. As the algorithmic approach helped to identify the steepest, least usable area on the site, this has been omitted from hat which can be traversed by the wires. The fastening system consists of hooks to which the wire is tied in a fishing uni tie.

3. The sitting well: the mesh material insert has been situated in the space that has been omitted from the gridshell “shortest route” tensile system. This provides a seat for one person at the steepest point on site. As a result, the user not only engages with the natural topography of the site, but is also offered the most effective, axial view towards Merri Creek.

Bibliography

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Hoisting.be,. 2015. ‘2-Legs Chain Sling - Lifting Chains And Hooks - Chains Grade 100 - Lifting Equipment - Hoisting Equipment’. http://www.hoisting.be/en/hijsmaterialen/detail/ketting-2-sprongen1/147/.

Lesker.com,. 2015. ‘Kurt J. Lesker Company | KF (QF) Cast Clamps (Aluminum) | Vacuum Science Is Our Business’. http://www.lesker.com/newweb/flanges/hardware_kf_clamps_machined.cfm?pgid=al2.

Holidayrentals.com,. 2015. ‘Canary Islands’ 5 Best Parks For Adults And Kids | Holiday Rentals Blog’. http://www.holidayrentals.com/blog/canary-islands-5-best-parks-for-adults-and-kids/.

Wdy.h-cdn.co,. 2015. http://wdy.h-cdn.co/assets/cm/15/10/54f5fd1b3ea74_-_01-woman-sitting-posture-pav5qs-lgn.jpg.

NBC News,. 2015. ‘Can You Do This? Simple Sitting Test Predicts Longevity’. http://vitals.nbcnews.com/_news/2012/12/13/15870881-can-you-do-this-simple-sitting-test-predicts-longevity.

Thetreehouseguide.com,. 2015. ‘The Treehouse Guide - Reduce Tree Damage Caused By Tree Houses’. http://www.thetreehouseguide.com/treedamage.htm.