<p>Drained triaxial testing is a fundamental method for determining soil mechanical properties, but variations in apparatus configurations (e.g., loading platen rotation) and testing procedures (e.g., initial specimen tilting) can introduce measurement deviations. This study investigates how these factors influence the mechanical responses of granular soils with varying initial densities using the discrete element method (DEM). Results show that non-rotatable loading platens minimally affected loose and medium-dense specimens but significantly increased deviatoric stress and volumetric dilation in dense specimens during the post-peak shear stage. Dense specimens with non-rotatable platens were more likely to develop “X”-type shear bands. The fabric anisotropy of dense specimens, characterized by changes in the dip angle and direction of contact orientation and normal forces, was influenced by loading platen rotation and initial tilting. Dense specimens exhibited greater sensitivity to loading platen rotation due to their more pronounced fabric anisotropy, which led&#xa0;to the persistent tilting of the loading plate in a single direction. Initial tilting of specimens, regardless of density, resulted in slightly higher deviatoric stress due to the induced deviation of the principal stress axis from the loading direction. The study highlights the significant impact of loading platen rotation on the strength and deformation behavior of dense sands and its correlation with fabric anisotropy.</p>