<p>As recognized geological barriers for radioactive waste disposals, natural claystone formations are critical to ensuring environmental safety. Excavation Damage Zones (EDZs) will be formed by the necessary man-made excavation activities. Variations in properties of the claystone induced by excavation are always a major concern. In this study, deformations of an unsaturated claystone sample in a triaxial compression test were monitored by a combination of X-ray micro-tomography and Digital Volume Correlation (DVC). Full-strain fields in the tested sample were obtained under different deviatoric stress levels. Variations of axial and radial strain fields under loading and unloading conditions are analyzed and discussed in detail. Significantly, this paper presents a first detailed investigation on different morphological hard inclusions. The obtained results indicate that strain fields of the unsaturated claystone sample in the triaxial compression test are non-uniform and strongly influenced by bedding planes. Widely distributed small hard inclusions induce more significant local concentration strains with respect to an isolated large particle. This research provides novel insights and essential guidance for multi-scale modeling and deformation prediction models. </p>