ABSTRACT
The aim of structural design is to ensure that, with an acceptably high probability, a structure will remain fully functional during its intended life. The expected lifetime of a structure is formally known as its design life and for permanent buildings is usually 50 years. During its design life, a structure must be capable of safely carrying all applied loads and other stress-inducing actions that might reasonably be expected to occur. Thus, it is necessary to identify and, more importantly, quantify the various types of load that act on its members. The different classes of loads that commonly act on structures and must be considered in design are the subject of this chapter. Due to the variable nature of most loads and materials, structural design philosophy relies heavily on the use of statistical principles. The application of these principles to ensure structural safety is discussed in Section 3.7.
