Rock Deformation

Abstract

In the case of rocks, terms used in conventional stress analysis to define stress-strain relations in ideal materials — such as elasticity, plasticity and viscoelasticity — are not easily justified. Fairhurst, in his foreword to Jaeger and Cook (1969), summarizes the position very well:

… problems of rock behaviour involve considerably more than selecting appropriate elastic constants and strength parameters and inserting them into elementary theories of continuum mechanics … Although rock obeys the same laws of mechanics as other materials, there are sufficient differences in behaviour, and emphasis in methods of approach, to warrant the distinctive term ‘rock mechanics’ … Inelastic deformations are, in fact, often of major significance in determining the stability and safety of structures in rock.