ABSTRACT
As stated at the beginning of Chapter 1, in civil engineering a soil may be taken to include any loose sedimentary deposit. This could include sand, clay, gravel, marl, etc. In order to be able to discuss the properties of different types of soil it is first necessary to have some way of classifying them. There are several ways in which a soil may be classified: by geological origin, by mineral content, by grain size or by plasticity. The last two are most widely used by engineers, and will be dealt with in this chapter.
