Effect of anisotropy on shear behavior of Hormoz carbonate sand

Anisotropy is one of the inherent characteristics of sedimentary deposits, which affects the behaviour of soils. Owing to the abundance of calcareous sands in many coastal and offshore areas and the construction of massive structures in these regions, investigating the effect of anisotropy on the shear strength of these types of soils is necessary. However, only few studies have investigated the influence of anisotropy on the behaviour of carbonate soils. In this research, the anisotropic behaviour of the carbonate sands of Hormoz Island, which is located north of the Persian Gulf, was investigated through rotating the bedding plane relative to the shear plane utilising a modified direct shear apparatus. The experimental investigations were conducted on different specimens with various densities and normal stresses in dry and saturated conditions. The experimental results evidently show that the effect of anisotropy is strongly related to the normal stress and density of the specimens. In addition, the effect of anisotropy is pronounced at high normal stresses for relatively dense samples. Furthermore, the samples at dry and saturated conditions reflected similar behaviour.