ABSTRACT
699The revisiting of some fundamental problems of rock mechanics, such as cracks in stressed rocks, propagation of surface waves, beam bending and axial splitting among others, viewed in the light of a strain gradient elasticity theory, reveals the necessity of enriching elasticity of rocks with length parameters to model surface energy of free surfaces and predict non-classical dispersion phenomena and size effects. After a brief review of the formalism and applications of a linear elasticity theory with microstructure for the study of static and dynamic problems, two problems are further presented here, namely the bending of beams and the axial splitting of deep geological layers. It is demonstrated in both studied problems, that the consideration of internal length scales are responsible for the manifestation of size effects.
