Cyclic loading and unloading true triaxial tests on remolded loess

Aiming at the development characteristics of cumulative plastic strain of loess under different stress paths under cyclic loading and unloading conditions, the remolded loess is taken as the research object, and the round-trip loading and unloading tests under different stress paths are conducted using a true triaxial apparatus to explore the influences of different stress paths and amplitudes on the cyclic stress time-history curve, hysteresis curve, backbone curve and cumulative plastic strain curve of loess. The results reveal the effects of the stress paths on the mechanical properties of the remolded loess, describe the correlation among each principal stress, ratio of the intermediate principal stress and the stress amplitude, and the hysteresis curve of the remolded loess is proposed to be approximately elliptical, with the slope of the major axis increasing with the increase of the ratio of the principal stress and decreasing with the increase of the stress amplitude. As the value of the ratio of the principal stress ratio increase, the backbone curve of cyclic stress-strain hardens accordingly, the cumulative plastic strain curve decreases in sequence, and the cumulative plastic strain develops earlier and enters a gentle stage. The research results provide a reference for solving the relevant problems in loess engineering.