Modelling forms an implicit part of all engineering design but many engineers engage in modelling without consciously considering the nature, validity and consequences of the supporting assumptions. Derived from courses given to postgraduate and final year undergraduate MEng students, this book presents some of the models that form a part of the typical undergraduate geotechnical curriculum and describes some of the aspects of soil behaviour which contribute to the challenge of geotechnical modelling. Assuming a familiarity with basic soil mechanics and traditional methods of geotechnical design, this book is a valuable tool for students of geotechnical and structural and civil engineering as well as also being useful to practising engineers involved in the specification of numerical or physical geotechnical modelling.