What is structural design?

The Moriyama House, Tokyo. One of
the projects of Structured Environment.
Image from Danda.

I listened to a lecture recently by Dr. Alan Burden, a Japan-educated British, and founder of Structured Environment, a Japan/UK-based structural design firm. Here's his take on what is structural design.

Firstly, he describes structural design as being a rare activity in modern society, because it blends technical and creative elements together in the same job.

Of course, structural design is not the only such "rare activity." In a way, many new artforms today are like that. Web design, digital videography and photography. And so on.

But I think Dr. Burden's definition is one for civil engineering in general. I recall in undergrad school, a professor defined civil engineering in class as (something like) "the art and science of utilizing the elements of nature for the benefit of humankind."

The art part comes with the uniqueness of almost every structure. Each house, each building, each bridge, each pylon, and so on is unique. Just as every artwork - the Mona Lisa, the Sistine Chapel ceiling, etc. - is unique.

You cannot put the same building, for example, in two different places, because the soil conditions might be different. Or, there might be similar soil conditions, but in one place you might need to consider large earthquake and typhoon loads, but not on another. And so on. That last example is exactly what happened to some Danish wind turbines (which are structures themselves) that some "smart" people thought could be installed in Japan, without modification. All they needed to realize their lack of civil/structural engineering art+science knowledge was one typhoon that toppled all of them down.

Dr. Burden also contrasted engineering with science, stating that scientists research natural phenomena, where there is a "correct" answer. Engineers, meanwhile, conceive things that have never before existed.

Of course, engineers use science (the technical element) to arrive at their designs. To me, engineering is application of science (including math) to practical use. Structural design involves physics, material science, statistics, matrix mathematics, and in a number of cases, seismology, meteorology, and hydrology.

But additionally, I think engineers also try to resolve things that science has not yet found the "correct" answer for, to help make our dreams come true in our lifetimes. For example, science cannot yet predict when and where will the next earthquake occur, and how strong it will be. Meanwhile, we want to already construct our dream homes, we want to get to our hometowns sooner which makes that bridge very important, and we want clean water delivered to our homes and not have to pump it out of the ground. And so on.

As a structural engineer, one of the most common questions I hear from clients is "Under what earthquake magnitude can this building stand to?" The truth is, structural designers don't really know. There is a lot of uncertainty in how buildings and faultlines that cause earthquakes behave. Many structural designers might throw out a number, and you might like them for it. I know you just want an answer. But the truth is, no one knows exactly. Those structural engineers certainly don't know. And personally, I think that "truth in advertising" is lost in those instances whenever they make those kinds of statements. As clients, you likewise could probably ask better questions. In the same way that you shouldn't buy a certain computer or phone and so on (which were likewise designed by engineers) just because you can; you should ask yourself first whether you really will need the things it can do.