Gilles Duveau

Anisotropic poroplasticity in saturated porous media, effect of confining pressure, and elevated temperature

This chapter presents some fundamentals of the poroplasticity theory for saturated porous materials. The theoretical background of the poroplasticity in anisotropic conditions is first recalled. The concept of effective stress for plasticity is revisited and discussed. Some experimental results from a typical porous rock are presented to check the validity of effective stress concept in plasticity. While different methods available for the description of anisotropic plasticity and failure are shortly resumed, the approach based on the fabric tensor theory is presented. As an example, the class of sedimentary rocks with parallel bedding planes is considered. Some numerical results obtained from a coupled finite element modeling of a gallery excavation are presented. The effects of material anisotropy on the plastic deformation and fluid pressure distribution are discussed. Some experimental data are finally presented showing the effects of temperature on the plastic deformation and failure properties of a sedimentary anisotropic rock.