Basic Structures for Engineers and Architects

In this chapter you, the reader, are introduced to structures. We will dis- cuss what a structure actually is. The professional concerned with struc- tures is the structural engineer. We will look at the role of the structural engineer in the context of other construction professionals. We will also examine the structural requirements of a building and will review the var- ious individual parts of a structure and the way they interrelate. Finally you will receive some direction on how to use this book depending on the course you are studying or the nature of your interest in structures.

Stress is internal pressure. A heavy vehicle parked on a road is applying pressure to the road surface – the heavier the vehicle and the smaller the contact area between the vehicle’s tyres and the road, the greater the pres- sure. As a consequence of this pressure on the road surface, the parts of the road below the surface will experience a pressure which, because it is within an object (in this case, the road) is termed a stress. Because the ef- fect of the vehicle’s weight is likely to be spread, or dispersed, as it is trans- mitted downwards within the road structure, the stress (internal pressure at a point) will decrease the further down you go within the road’s con- struction.

The various types of structural element that might be found in a build- ing – or any other – structure were introduced in Chapter 1. Now we’ve learned about the concepts of compression, tension, bending and shear, we’ll discuss how these different parts of a structure behave under load.