Structures by Design

Thinking, Making, Breaking

Rob Whitehead

• Publisher: Routledge
• Year: 2019
• ISBN:
  9781315403120
• Edition: 1
• Topic: Arquitectura
• Subtopic: Métodos y materiales arquitectónicos

*Winner of the 2021 TAA Textbook Excellence Award*

Honorable Mention of the 2021 BTES Book Award

Structures by Design: Thinking, Making, Breaking is a new type of structures textbook for architects who prefer to learn using the hands-on, creative problem-solving techniques typically found in a design studio. Instead of presenting structures as abstract concepts defined by formulas and diagrams, this book uses a project-based approach to demonstrate how a range of efficient, effective, and expressive architectural solutions can be generated, tested, and revised.

Each section of the book is focused on a particular manner by which structural resistance is provided: Form (Arches and Cables), Sections (Beams, Slabs, and Columns), Vectors (Trusses and Space Frames), Surfaces (Shells and Plates), and Frames (Connections and High-Rises).

The design exercises featured in each chapter use the Think, Make, Break method of reiterative design to develop and evaluate different structural options. A variety of structural design tools will be used, including the human body, physical models, historical precedents, static diagrams, traditional formulae, and advanced digital analysis.

The book can be incorporated into various course curricula and studio exercises because of the flexibility of the format and range of expertise required for these explorations. More than 500 original illustrations and photos provide example solutions and inspiration for further design exploration.

PART 1

Learning to Think, Make, and Break

Figure 1.0.0 Body-like column forms at Dulles Airport Terminal (Saarinen, 1964)

CHAPTER 1.0

Body Structures

The Feel of Things

Are you sure this is architecture?

(Beginning design student, during lab, at Iowa State University)

You probably know more about structural design than you’d expect. The trials and errors of our physical experiences have prepared us to connect what we “feel” to what we’ll learn. By enacting particular poses in a mindful way and recording the results using principles of structural design, we’ll build a foundation of knowledge and develop a reliable learning tool to assist our design efforts.

Begin with Basics

Learning structures may seem difficult and complicated but it doesn’t have to be. Profound lessons about structural principles can be felt and understood by being mindful of what our bodies can teach us (or have already taught us)? Our bodies anticipate and adjust to the different structural conditions we face daily through trial and error. Throughout our lives we’ve subconsciously learned to “design” our body into responsive and effective structural forms. As Eduardo Torroja explained, “The process of visualizing or conceiving a structure is an art. Basically it is motivated by an inner experience, by an intuition.” We are all experienced structural designers already, we simply need to be mindful of the lessons we’ve learned.

The Feel of Things: Basic Support

Standing up straight, holding a child on your hip, or leaning over to pick up grocery bags without tipping over may not seem like profound accomplishments or structural lessons, but these simple acts pull, push, and twist different parts of the body—all fundamental structural actions. Because we’d rather not drop the child or the groceries or fall over, we’ve learned to adjust our “structural frame” to best resist these forces acting upon us—we adjust our body’s form because we can’t change our body’s “material” matter. Throughout our lives, responding to the basic challenges of structures: Stacking, spanning, and stabilizing, becomes routine. (Figure 1.0.1)

While these actions can be described, calculated, and diagrammed using mathematical and scientific principles, we didn’t wait to perform them until we had learned the structural principles behind them. This would be absurd, of course, but this has been the most common approach to structural education. As the architect, engineer, and shell builder, Felix Candela, observed, “what could be the progress of mankind if nobody were allowed to perform any jump or movement without a previous mathematical determination of the force that must be asked from a certain muscle?”

Figure 1.0.1 Body forms respond to common structural challenges

Compared to our bodies, conventional tools used in structural education (charts, diagrams, formula) aren’t easy to learn, can be laborious to use, and in their most basic representations they portray structures as flat, not spatial. Our bodies, though, can make simultaneous adjustments of different variables and evaluate the three-dimensional consequences of these changes quickly. In his essay, “The Feel of Things”, renowned structural engineer Fred Severud argued that body structures were more effective than calculations initially because, “Without having to go through all these mystifications, you can feel what happens in a structure.”

Figure 1.0.2 Different poses create different stresses

Consider how easily we can learn about the differences between arches and beams by simply acting out the differences. Try it. When you put your body in a traditional plank pose, your straight-backed torso acts like a beam spanning between your feet and hands. It’s hard to maintain this pose for long. Your hips sag due to the bending stress you feel. You may allow your hips to sag like a tensioned cable or to bend your waist and lift your hips into a compressed arch shape. Note that although you are spanning the same distance in all three forms (as a beam, cable, and arch) each pose feels different as a result of your body’s changing form. This may not seem remarkable but these simple acts reveal a profound lesson: There is an inescapable relationship between the form of a structure and how it behaves. (Figure 1.0.2)

THIS is the fundamental lesson that will be repeated throughout the book. When you understand relationships between forms and forces, you can design structures to be more responsive. Learning how to be a proactive structural designer will require different experiments and lessons; we will start with where we all started our structural education—our bodies.

Design Challenges: Spanning and Stacking

For the remainder of the chapter you will be challenged to create different types of structural solutions as individuals and in groups using primarily your bodies. These poses will reveal basic structural principles and behaviors. The structural challenges are simple and intentionally open-ended:

Challenge #1: How high can you reach? Measure from the ground to the highest point.

Challenge #2: How far can you span? Clear span is the distance between supports (your feet), but you should also try to maximize the overall length your bodies can reach from end to end.

THINK, MAKE, AND BREAK: ASSESSING ACTIVITIES

One of the critical lessons to learn about the Think, Make, and Break method is knowing what information you are hoping to find at each stage of the process. Before you begin, think strategically about what you are planning to do and why it might, or might not work. All useful experiments start with a considerate hypothesis (“think”). Next, go through the entire process of “making” all these structures; you may learn certain strategies from one exercise that helps you in another. As you act these out, be mindful of your posture, placement of “supports,” and locations inside your body where you feel stresses. Gather objective data by documenting these poses with photos, notes, and measurements taken from different perspectives so you can see your body as a three-dimensional construct—compare how the structure behaves or “breaks” back to your hypothesis. To make sure the act of “breaking” is productive, you’ll need to be specific about what sort of information you are hoping to learn as a result. Record your activities in a lab report including answers to specific question about “what I learned” based on the assigned objectives. (Figure 1.0.3)

Figure 1.0.3 Body structure experiments (SxD, Iowa State University)

Breaking: Confirming Experiences

Consider how you can translate your physical activities to useful lessons. Some of these poses may seem routine, difficult, or fun, but look beyond the experience itself. If a pose is difficult or doesn’t work, try to determine why. The goal is to visualize and document the hidden structural behaviors that you are experiencing into the language of structural design principles. Enacting these will produce results and reactions, but unless you record them, the lessons will be fleeting. The digital representations of body structures shown in this chapter will also include examples of how to describe, diagram and analyze structural principles: Forces, loads, equilibrium, supports and states of stress. The goal is to align the math and science of structures with your experiences. Document your work accordingly.

With each pose, answer the following questions:

Question #1: What is the primary type of stress you feel? Where do you feel it?

Question #2: How did the form change as the group size increases? Under what conditions was it beneficial to have more people?

Question #3: What complications arise the hig...