Abstract: Analysis of the cracking levels (micro/macro crack initiation, propagation and coalescence) in shales subjected to different loading conditions will provide important information for constitutive/numerical analysis as well as the rheological response of the material. In this research, hydro-mechanical and hydraulic fracturing characterization of natural and resedimented Opalinus clay shale subjected to triaxial loading conditions along with their microseismic and microstructural properties are investigated. From a fundamental research point of view, this project will provide a major contribution to current challenges regarding the geomechanical behaviour of shales applicable by both: i) radioactive waste societies where shale formations are the concerned geomaterials for disposal of high-level radioactive wastes; and ii) petroleum engineering societies for unconventional exploitation of shale gas.