;This study is to investigate the surface failure behavior and the underlying soil mechanics mechanism in the vicinity of normal fault. Near the fault can be observed in the vicinity of the fault caused by a large number of soil deformation, but the mechanical changes under the surface can not be seen with the naked eye In this study, PFC2D was used to simulate, because PFC (Particle flow code) was simulated by particle flow, and the mechanical behavior was more close to the experimental sandbox. The measure circle was discussed in the upper and lower sides of the normal fault Mechanical Behavior and Microstructure Variation of Soil Near the Shear Zone in Faults. For the change in porosity during dislocation, it can be seen that most porosity values did not change in the lower panel. For areas near the shear zone, the porosity increases significantly in the upper plate area (shallow soil location). The porosity increases slightly in the bottom area near the shear zone (deeper in the soil). For the change of the stress path and the rotation angle, the stress path is compressed in the lateral direction and then decompressed in the vicinity of the initial value. The change value is within 20 kPa and the rotation angle changes in the positive and negative 5 ° or less, on behalf of away from the shear zone of the stress change is not significant. However, the stress path in the vicinity of the crack zone is axially decompressed after axial compression, especially in the area above the shear zone, and its stress path is more complicated.
