The second edition of this well established book has been comprehensively updated in line with recent developments. After presenting the fundamentals of stress and strain, and their graphical representation, the book includes chapters on failure states in soils and rocks, observed and elastic paths, and the use of discontinuities. New sections include shear bands and small strain behaviour, as well as the use of elastic shear modular stress calculations and discontinuities in plasticity calculations. Expanded coverage is also given to dilitancy of soils and roughness of rock joints.