Strength and structural anisotropy of loess

Undisturbed loess is the structural soil with anisotropy, and its anisotropy has great influences on the stability of slopes, tunnels and underground structures with complex stress state.To study the strength and structural anisotropy of loess, the unconfined compressive strength tests are carried out on the undisturbed and remolded loess samples with different sampling angles(0°, 30°, 45°, 60°and 90°)and different water contents, and the unconfined compressive strength of the corresponding specimens are obtained.The initial structural parameters are calculated.The relationship among the unconfined compressive strength, structural index, soil sampling angle and water content of loess is analyzed.It is found that the strength and structure of loess are the strongest when the sampling angle is 90°and the weakest when the sampling angle is 30°in the tests.The lower the water content, the stronger the strength and structure.With the increase of the water content, the strength and structural anisotropy of undisturbed loess decrease gradually and are the lowest at saturation.