To investigate the influence of initial moisture content on the mechanical properties of unsaturated loess, this paper focuses on unsaturated loess with varying initial moisture content. Isotropic compression tests at constant moisture content and true triaxial shear tests were conducted. By controlling suction and net mean stress, the relationship between void ratio and net mean stress was analyzed to determine the yield point and yield stress. Furthermore, the effects of confining pressure, saturation, dry density, and clay content on yield characteristics were explored. The experimental results indicate that under isotropic compression at constant moisture content, the void ratio decreases with increasing net mean stress. The e-lnp curve is approximately composed of two intersecting straight lines, with the intersection point representing the isotropic compression yield stress. Both yield stress and yield suction increase with the increase of initial suction. The slopes of the straight lines before and after yielding are less affected by initial suction. Moisture weakens the structural yield characteristics of loess, and the yield stress of different soil samples exhibits varying trends with increasing saturation. The study reveals that initial moisture content significantly affects the LC yield characteristics of unsaturated loess. Yield stress is closely related to saturation, dry density, and clay content. The research findings provide a theoretical basis for the engineering application of unsaturated loess.
