The evolution of fabric under loading plays an important role in the micromechanical analysis of granular materials. This paper addressed this issue from the perspective of the discrete element method (DEM) simulation. A series of drained tests were performed under true triaxial stress conditions. Isotropic assemblies with different densities were sheared to the critical state under three kinds of loading paths. The evolution of three-dimensional fabric under general stress conditions was investigated by analyzing the influences of density, shear mode, and loading path on the fabric anisotropy. Numerical results revealed some evolution patterns of fabric with strain and stress. The evolutions of fabric components and deviatoric fabric were dependent on shear mode. An ultimate fabric anisotropic state was achieved at a relatively large strain for a given shear mode, which agreed with the theoretical expectation of anisotropic critical state theory. Noncoaxialities between fabric, stress, and strain tensors were also observed in simulations and these noncoaxialities needed to be rationally incorporated into fabric evolution laws.

When excavating a tunnel, the stresses are distributed asymmetrically along the tunnel cross-section. Other factors, particularly slope friction force and excavation speed, can also contribute to the deformation and displacement of a tunnel. Despite this, several authors have used the complex potential method to predict the ground deformation surrounding the tunnel. However, their applicability to the ground response caused by the asymmetric stress distribution around the tunnel wall is analysed in this context. This paper, therefore, proposes an approximate solution on the slope to predict the tunnel cross-section deformation. The solution is based on the complex potential method to predict analytically and numerically the ground deformation around the tunnel. However, two variables called the “complex potential functions” for the Laurent series expansion are used for the stress redistribution to the tunnel boundary conditions. Data from the Qijiazhuang tunnel case are used to justify the proposed analytical solutions. This solution is an essential guide for analyzing deformations in complex geological conditions and structures, such as steeper slopes.