Influence of a preset fissure on clay behavior under uniaxial compression

Under compression, the flaws in soils will not only weaken the mechanical properties of soils, but also affect the strain localization of soils. In order to study the influence of flaws on the behavior of soils under compression, the uniaxial compression tests of clays with different inclination and position fissures were carried out, and the two-dimensional numerical analysis was also discussed based on the damage plasticity model. Analyzing the results of the uniaxial compression test and simulation of the intact and fissured clays, the following conclusions can be drawn: (1) The 60-degree fissure located on the upper position of the right edge of the clay has the greatest influence on the failure form and damage energy of clays, which can reduce the compression strength by 30% compared with that of the intact clay. (2) The numerical method based on the damage plasticity model can basically simulate the compression behavior of clays containing a pre-existing fissure and reproduce the failure characteristics of clays. (3) The preset fissure has obvious influence on the evolution of maximum principal stress in the area with serious damage, but less on the shear stress. And in the area with slight damage, the effect on the maximum principal stress and shear stress is very weak.