This project focuses on fluid flow in porous materials with evolving microstructure in the context of civil engineering applications and geomechanics. When the distribution of cracks and the distribution of pore size evolve in concrete and rocks, the influence on the permeability in the case of a single or a multiphase fluid flow needs some in depth investigation. A recent review of state of the art in modelling progressive mechanical breakdown and associated fluid flow in heterogeneous rock shows that little is known on the coupled effects between micro cracking and the intrinsic permeability of a solid phase. The present project intends to tackle this relationship between mechanical breakdown and associated fluid flow in the context of poromechanics extended to non local modelling. In particular, we will investigate how the internal length which plays a pivotal role at the inception and propagation of material failure may interact with the permeability, what enhanced Darcy-like relationship might be derived in order to apprehend such effects and how to model fluid flow in tight porous materials. The models will be extended to complex and multicomponent systems reproducing as closely as possible the behaviour of real fluids in order to understand and to describe the thermodynamical behaviour due to confinement such as modification of phase transitions and capillary condensation. The principal investigator of this project is a specialist in the field of continuum damage mechanics, failure due to strain and damage localisation. He has been the founder and among the major promoters of non local damage modelling, which is today a state of the art model in computational structural failure analyses. After a decade of research on durability problems for which he was elected at Institut Universitaire de France, his research interests recently turned toward petroleum engineering, the focus of the research team he joined two years ago at université de Pau.