Structural Engineering

Structural Engineering is a field of engineering dealing with the analysis and design of structures that support or resist loads. Structural Engineering is usually considered a specialty within Civil Engineering but, it can also be studied in its own right. Structural Engineers are most commonly involved in the design of buildings and large nonbuilding structures but they can also be involved in the design of machinery, medical equipment, vehicles or any item where structural integrity affects the item's function or safety. Structural Engineers must ensure their designs satisfy, given design criteria, predicated on safety (e.g. structures must not collapse without due warning) or serviceability and performance (e.g. building sway must not cause discomfort to the occupants). Buildings are made to endure massive loads as well as changing climate and natural disaster.

Structural Engineering theory is based upon physical laws and empirical knowledge of the structural performance of different landscapes and materials. Structural Engineering design utilises a relatively small number of basic structural elements to build up structural systems that can be very complex. Structural Engineers are responsible for making creative and efficient use of funds, structural elements and materials to achieve these goals. Structural Engineers are responsible for engineering design and analysis. Entry-level structural engineers may design the individual structural elements of a structure, for example the beams, columns, and floors of a building. More experienced engineers would be responsible for the structural design and integrity of an entire system, such as a building.

Structural Engineers often specialize in particular fields, such as bridge engineering, building engineering, pipeline engineering, industrial structures, or special mechanical structures such as vehicles or aircraft.

Structural Engineering has existed since humans first started to construct their own structures. It became a more defined and formalised profession with the emergence of the architecture profession as distinct from the engineering profession during the industrial revolution in the late 19th Century. Until then, the Architect and the Structural Engineer were usually one and the same - the master builder. Only with the development of specialised knowledge of structural theories that emerged during the 19th and early 20th centuries, did the professional Structural Engineer come into existence.

The role of a Structural Engineer today, involves a significant understanding of both static and dynamic loading and, the structures that are available to resist them. The complexity of modern structures often requires a great deal of creativity from the Engineer, in order to ensure the structures support and resist the loads they are subjected to. A Structural Engineer will typically have a four or five year undergraduate degree, followed by a minimum of three years of professional practice before being considered fully qualified.

Structural Engineers are licensed or accredited by different learned societies and regulatory bodies around the world (for example, the Institution of Professional Engineers in NZ - IPENZ).  Depending on the degree course they have studied and/or the jurisdiction they are seeking licensure in, they may be accredited (or licensed) as just Structural Engineers, or as Ciivil Engineers or, as both Civil and Structural Engineers.

History of Structural Engineering

Structural Engineering dates back to 2700 BC when the step pyramid for Pharaoh Djoser was built by Imhotep, the first engineer in history known by name. Pyramids were the most common major structures built by ancient civilizations because the structural form of a pyramid is inherently stable and can be almost infinitely scaled (as opposed to most other structural forms, which cannot be linearly increased in size in proportion to increased loads.

Throughout ancient and medieval history most architectural design and construction was carried out by artisans, such as stone masons and carpenters, rising to the role of master builder. No theory of structures existed and, understanding of how structures stood up, was extremely limited and, based almost entirely on empirical evidence of 'what had worked before'. Knowledge was retained by guilds and seldom supplanted by advances. Structures were repetitive and increases in scale were incremental. No record exists of the first calculations of the strength of structural members or the behaviour of structural material but, the profession of structural engineer only really took shape with the industrial revolution and the re-invention of concrete (see History of concrete). The physical sciences underlying Structural Engineering began to be understood in the Renaissance and have been developing ever since.

The history of Structural Engineering contains many collapses and failures. Sometimes this is due to obvious negligence, as in the case of the Pétionville school collapse, in which Rev. Fortin Augustin said that "he constructed the building all by himself, saying he didn't need an engineer as he had good knowledge of construction" following a partial collapse of the three-story schoolhouse that sent neighbours fleeing. The final collapse killed at least 362 people, mostly children.

In other cases structural failures require careful study, and the results of these inquiries have resulted in improved practices and greater understanding of the science of Structural Engineering. Some such studies are the result of Forensic Engineering investigations where the original engineer seems to have done everything in accordance with the state of the profession and acceptable practice yet a failure still eventuated. A famous case of structural knowledge and practice being advanced in this manner can be found in a series of failures involving Box girders which collapsed in Australia during the 1970s.