What is Structural Engineering

Structural engineering is a branch of civil engineering and/or architectural engineering that is an essential component of multiple industries. Structural engineering in its most basic form entails, designing a structure with the least amount of resources so that it may perform its intended function safely for the life of the structure. 

Other fun definitions of what engineers do that we have heard over the years include:

  • “Someone who designs for a dollar what any person could do for two”
  • “Someone who does precision guesswork based on unreliable data provided by those questionable knowledge”
  • “Someone who solves a problem you didn’t know you had in a way you don’t understand”

Why Structures Fail

Every structure is subject to the effects of environmental loads such as wind and earthquakes and internal loads including occupants and the self-weight the structure due to gravity. The loading that a structure is required to support is typically governed by codes enforced by the Authority Having Jurisdiction (e.g. building codes such as the International Building Code). Code minimum loads are derived from historical records and statistical analysis to provide a reasonable level of confidence that they will not be exceeded in a given time period.

The members of the structure and their connections must be proportioned to adequately transfer these loads from each other and ultimately into the Earth (soil, bedrock, etc.). Structures can fail for numerous causes with the majority of them falling into one of the categories below:

  1. The environmental or internal loading on the structure exceeded that for which it was designed for.
  2. The structural members and/or connections where not adequately propositioned for the loading.
  3. The structure was not constructed per the design.

Historical Progression of Structural Engineering

Historically, structures were constructed that withstood these loads over long periods of time primarily using empirical processes (rules of thumb and past experience). Examples of these structures include the Great Pyramids of Giza, and the Roman Colosseum.

Great Pyramids of GizaRoman Colosseum

Today, modern structures are designed and constructed by applying principles derived from the fields of  mathematics and physics, (Applied Science – is the application of existing scientific knowledge to practical applications). Applying these principles, allows structural engineers to utilize analytical in lieu of empirical methods to adequately predict the behavior of a structure to said loading and then subsequently design the structure to safely support it.  This has led to substantial reductions in the cost of construction as well as great improvement in performance.

Structural Gravity Load PathStructural Lateral Load Path

What Makes a Great Structural Engineer

In reference to basic purpose of a structural engineer “designing a structure with the least amount of resources so that it may perform its intended function safely for the life of the structure”, a great structural engineer is one who is well versed with modern analytical methods, building codes, and construction materials and has the confidence to apply this knowledge to provide the Client with a safe and functioning structure for the least cost.