Study on the progressive fracturing in soil and rock mixture under uniaxial compression conditions by CT scanning

Abstract Soil and rock mixture (SRM) is very common in engineering as a type of extremely heterogeneous and anisotropic geological material. SRM is easy to fracture and damage under external forces, which often causes geological disasters, such as landslide and debris flow. Therefore, study on the progressive fracturing of this material is very important for geological engineering. In this paper, uniaxial compression test with real-time computed tomography (CT) scanning was conducted on SRM samples (with rock percentage of 40%). The evolutions of visible fractures, invisible fractures in CT slices, average density and heterogeneity of the sample during loading process were all studied quantitatively. This research finds that invisible fractures occur soon once loading begins, gradually accumulate in elastic deformation stage, and finally form visible fractures in plastic deformation stage. Average density of the whole sample slightly declines, while heterogeneity greatly increases during the evolution of fracturing.