Takuhiro Wakita

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Step 1 - Generative Design Framework

I have experience exclusively in infrastructure projects, and thus I have tailored this framework specifically to suit such endeavors. The initial design decision pertains to the viaducts of the Shinkansen. The primary design variables involve determining the spacing between piers and the desired cross-sectional shapes. In order to assess the design, key evaluators encompass concrete volume, structural strength, and construction cost.

Another case that I have conceived involves the design of roadside trees. Pertaining to the design variables, the average height of the trees and the size of their canopies prove instrumental in determining the appropriate tree species. Additionally, the spacing between the trees can be considered a variable. As for the evaluators, they encompass the total shading area provided by the trees, the associated maintenance cost (which relates to tree height and canopy volume), and the annual reduction in CO2 emissions.

Lastly, I have contemplated the design of box culverts as a third option. Crucial design variables include the inner height, inner width, as well as the slab and wall thickness. Regarding the evaluators, I would select concrete volume, structural strength, and construction cost.

  • Viaducts of Shinkansen:
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  • Design Variables
    • Distance between piers
    • Cross-sectional shapes
  • Evaluators
    • Concrete volume
    • Structural strength
    • Construction cost
  • Most Important Tradeoffs to Consider
    • Concrete volume vs Structural strength
  • Roadside Trees:
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  • Design Variables
    • Average height of trees
    • Average size of the canopy
    • Pitches of trees
  • Evaluators
    • Total shading area provided by the trees
    • Maintenance cost (related to tree height and canopy volume)
    • Annual CO2 reduction
  • Most Important Tradeoffs to Consider
    • Maintenance cost vs Annual CO2 reduction
  • Box Culvert:
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    2. Design Variables
      • Inner height
      • Inner width
      • Thickness of slab and walls
    3. Evaluators
      • Concrete volume
      • Earthwork volume
      • Waste of soil after backfilling
      • Structural strength
      • Construction cost
      • Inner space
    4. Most Important Tradeoffs to Consider
      • Inner space vs Earthwork volume

Step 2 - Generative Design Study

  • Objective

Box culvert is very common structure, thereby it is very useful to automatically generate a lot of design options. Of course, we want to maximize inner space and cross section area. For instance, for sewer water, it means that we can treat much water with it. On the other hand, we want to minimize the concrete volume.

  • Model

I defined the cross section as below. I separately define inner and outer curves. I describe outer rectangular shape with red lines. In addition, I define the inner shape with 8 points shown with black lines. I also give a relationship between the thickness and inner width of the box culvert because of the deflection constraint. I determined it with the equation. t = W/10

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t: Thickness of slabs and walls

W: Inner width

H: Inner height

a: Length of haunch

  • Design Variables

I set three variables, Inner width, Inner height and Length of haunch. As explained above, the thickness is determined by the inner width.

  • Constants

I used the length of box culvert as 150 ft.

  • Evaluators

I set three evaluators, inner space, cross section area, and concrete volume.

Dynamo graph

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This part shows the inputs of the Dynamo graph.

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This part is for determine 8 points of the inner geometry.

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This part determines the points for the outer shape.

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In this part, I generated the inner solid model.

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In this part, I determined the outer solid.

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I obtained evaluators from this part.

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Step 3 - Generative Design Study Results

The below I show the result of my generative design study.

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These are scatter plots between variables and evaluators.

It’s obvious that Inner space and Concrete Volume have a linier relationship so it can be said that maximizing inner space and minimizing concrete volume are trade-off as shown in the top figure. In addition, the slop changes in the middle. It is possible that this is because H reaches max at the point and according to the increase of W, t become greater.

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Haunch length and inner space have a relationship of tread-off at some point but the impact haunch is relatively small.

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Haunch length and concrete volume are also trade-off. However, the scale of haunch is too small to have a lot of influence to it.

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