ABSTRACT
Construction and building of engineering structures in geomaterials with soil and rock mixture (SRM) are often challenging tasks for engineers. While the macroscopic mechanical properties have been widely studied, the physical meso-scale mechanisms governing the SRM deformation are still poorly understood. In this chapter, we applied a high-energy X-ray computed tomographic (CT) imaging method to study the mesoscopic structural changes in bimsoil and the associated strain localization behaviors. A series of uniaxial and triaxial compression experiments were conducted for the bimsoil samples with rock block percentages (RBP) of 0%, 30%, 40%, and 50%, respectively, under various confining pressures. The meso-structural changes were quantitatively studied using the macroscopic stress–strain descriptions and the mesoscopic CT image identification. The shape of localized bands is extremely nonuniform and strongly affected by the existing rock blocks. The scale of the localized bands presents a reduction trend with increasing confining pressure. What is more, the most striking observation from the CT images is that the zone of localization may disappear during deformation owing to interactions between the soil matrix and rock blocks. Through a series of meso-structural evolution analyses, the meso-mechanisms of bimsoil samples under static loading paths have been documented.
