Mesostructure Evolution of Gravelly Soil under the Triaxial Compressive Condition by Computerized Tomography

Gravelly soil is widely used in many engineering construction projects, partly due to its extensive distribution and rich reserves in nature. Using special purpose loading equipment, the computerized tomography (CT) real-time tests were conducted to investigate the mesomechanical behavior of gravelly soil under the triaxial compressive condition. Mesostructure evolutions of soil particles, such as particle motion law and long axis direction, as well as the relation to macroscopic phenomenon were studied through the quantitative analysis of CT number and CT images. Results show that the mean CT number decreases, but the standard deviation increases with the increasing axial strain, which indicates that internal structural defects of gravelly soil are intensified in the loading process. Position adjustment and long axis evolution of particles reflect behaviors of particle rearrangement and anisotropism development during the triaxial compressive process. Experimental findings are helpful to revealing the mesomechanism of deformation of gravelly soil.