This book is an account on the thermomechanical behaviour of granular and porous materials and deals with experiments, theoretical deduction of macroscale equations by means of averaging from microscale properties, embedding the macroscopic description into a continuum-thermodynamical and statistical context and analysis of solutions of macroscopic models by numerical techniques. It addresses itself to engineers (chemical, civil, mechanical) applied mathematicians and physicists at the advanced student or Ph. D. level at universities, research centres and in industry.