Suitable for undergraduates of geotechnical engineering for civil engineers, this textbook sets out the basic theories of soil mechanics; combining both classical and critical state theories. It describes soil behaviour by relatively simple equations with clear parameters. It also includes experimental demonstrations to illustrate the principles. "Possibly the best text book for supporting an introductory course on soil mechanics, and one which is uniquely leavened by reference to everyday observations." - David White, Géotechnique