When you don’t work in the industry every day, structural and civil engineering terminologies can be confusing. We have therefore created a list below of our most common questions. If you have a terminology that you’re stuck on, contact us and let us know to add it to the list.
Abutment: the part of a pier or wall that is either an end of an arch, beam or bridge which resists the pressure of a load.
Aggregate: in construction used to describe granular materials such as gravel and sand. In concrete, fine aggregate (sand) and coarse aggregate (gravel) are essential constituents together with cement.
Architect: a profession which plans, designs, and reviews the construction of buildings to ensure they are aesthetically appropriate.
Beam: a structural member designed to resist bending; usually horizontal. Beams may also be inclined or cranked (with a bend in the vertical plane) to suit the shape of a roof, for example.
Bearing: the point of support for a beam, such as on a wall. The concentrated load on the bearing must be distributed into the supporting wall, and reinforced by a padstone if necessary. Bearing length is the length of beam resting on the wall.
Column: a vertical member designed to resist axial load (direct compression), such as the weight of a building. May be made of any suitable material such as concrete, masonry, steel or timber.
Compression: an axial force in the “pushing” or “squashing” sense; the opposite of tension. Columns are designed to resist compression, but it is also produced in bending of beams.
Dead Load: the force on a structure resulting from the weight of the structure itself. This is normally constant, except of course during construction or demolition when the changes in load need to be considered to ensure safety at each stage.
Deflection The change in shape resulting from the application of a force or load. Beams deflect due to bending, even when made of steel or concrete. Limiting deflection to an appropriate value is often the governing consideration in
Force: fundamental to engineering science, an influence that causes a body to change its speed, direction or shape. Structures are usually intended to resist movement, so the effect of the force is to change the shape of the structure, causing deflection. The stiffness of the structure determines the amount of deflection for a given force.
Foundation: the part of a structure that transfers the forces in the building into the ground. Being invisible, the importance of the foundation is often overlooked, but foundation failure is the most frequent and expensive cause of warranty claims. Inevitably, the strength of the soil supporting the foundations is critical to their performance and a good understanding of soil conditions is vital.
Imposed Load: the load imparted to a structure by the objects that it supports, such as people, furniture, vehicles and so on. Other imposed loads are caused by snow on roofs, for example. British Standards define values of imposed load to be used in design for various classes of
Joist: a beam usually arranged in parallel with others to support a floor, roof or ceiling. In domestic construction, these are usually of timber, but steel and concrete joists are also used.
Live Load: another term for Imposed Load.
Moment: a measure of force causing a turning effect
Needle Beam: a short length of timber or steel that is inserted through a hole in a wall, with props at each end to enable the wall to be supported while work takes place beneath.
Padstone: a piece of masonry designed to spread a concentrated load (such as the support reaction from a beam) into a structure. Commonly these are made from concrete either cast in-situ or
Portal Frame: a structural frame whose purpose is not only to support gravity loads in a vertical direction, but also to resist horizontal loads such as wind loads and sway forces.
Reinforced Concrete (RC): a structural material employing steel bars to improve the strength of concrete, which is very weak in tension on its own, to form a composite.
Span: the distance between the centres of
Strain: the measure of how much a material deforms under stress, i.e. the symptom. In tension, the strain is shown by the material stretching, for example. Each material will have a limiting strain at which interatomic forces can no longer resist the applied stress, and either plastic deformation or rupture occurs.
Structure: a system of components devised to support loads and/or resist forces. This includes buildings, but also bridges, dams, frames, aircraft, cobwebs and skeletons.
Truss: a structure composed of straight members connected in triangles, requiring no bending resistance in principle as the member forces are purely axial. Roofs and bridges are applications for which trusses are well suited.
Wind-Moment Frame: a type of structural frame that is simpler to design but less resistant to horizontal forces than a portal frame. Used where wind or sway loads are not critical.
Yield: the point at which the stress in a material exceeds its ability to behave elastically, that is to recover to the original shape on removal of the applied load.