Behaviour of deep shafts in rock considering nonlinear elastic models

Abstract Some models that consider the non-linearity of the stress-strain behaviour of rocks are reviewed and discussed in this work. The models are an extension of the classic elastic theory where the constant elastic modulus is replaced by a function, which relates the modulus of elasticity and the confining pressure. The analytical solutions for determining the stresses and strains induced by vertical excavations are compared with the linear elastic solution, considering the excavation at three different depths (250, 1000 and 2000 m). It is verified that the stresses and strains given by the non linear analysis can be very different from those given by the linear elastic analysis, depending on the relation between the elastic modulus and the confining pressure.