The Behavior of Gravel-Soil Interface During Triaxial Testing of the Mixed Soil

Through CT scanning, digital image processing, reverse engineering reconstruction, and 3D meshing, the numerical model of the mixed soil was established. On this basis, a numerical simulation of the triaxial testing was carried out. The movement of the 70 gravels was monitored and analyzed based on the proposed geometric feature point method (GFPM). The interaction between the gravels and soil during the triaxial testing was explained according to the spatial attitude of the gravels. The top gravels showed a dominant detachment with soil in the axial direction and an increasing detachment in the lateral direction. The gravels close to the side face of the triaxial specimen showed a dominant detachment in the lateral direction. The gravels rotated during the triaxial shearing process. The deformation of the gravel-soil interfaces near the shear zone was more significant. At the bottom of the specimen, the gravel-soil interface had no obvious deformation.