Abstract: This study investigates the strain development in saturated silty soil from Yellow River under varying initial consolidation inclination angles ξ by principle stress rotation tests. The results indicate that distinct patterns in axial, circumferential and torsional shear strains show the influence of ξ on the mechanical response of silty soil. Notably, the axial strain exhibits compressive behaviour at ξ =90° during the first cycle, while the circumferential strain displays tensile behaviour. Anisotropy initiates at around ξ =90° and ξ =60° for other ξ angles. Different values of ξ exhibit stabilization trends in strain fluctuations, with ξ =90° and ξ =75° showing intriguing similarities. The case of ξ =45° is distinctive, exhibiting the highest fluctuation and strain amplitude. Torsional shear strain similarities are observed among most ξ angles, except for ξ =90° and ξ =60°. Volumetric strain highlights the significant impact of consolidation angle inclination on anisotropic characteristics. As the initial solidification angle increases, the hysteresis curve shifts left, indicating cyclic creep characteristics, with negligible shear strain observed for ξ =60°. As the cycle period increases, the hysteresis loop contracts, indicating continuous strengthening and eventual stabilization of shear stiffness. This comprehensive study provides valuable insights into the complex behaviour of saturated silty soil under rotational stress conditions, highlighting the role of initial consolidation inclination angles in shaping its mechanical response.

Key words: hollow cylindrical apparatus, principal stress rotation, initial consolidation angle, silty soil, stress path