The researchers conducted tests on intact loess to understand its strength and deformation characteristics. They found that loess tends to fail plastically under different pressures and stress conditions. The stress-strain relationship curve shows hardening behavior. Loess deformations are nonlinear, with volume shrinking during shearing. Confining pressure has a greater impact on soil deformation than stress state. The intermediate principal stress coefficient decreases with increasing confining pressure and changes with stress state. Loess failure strength is influenced by stress conditions, with cohesion decreasing and friction angle increasing as stress state changes.