Experimental Study of Loess Mechanical Properties with Different Water Content

Loess is a special kind of sediment, which has the characteristics of loose structure, pore development, and poor cementation. Its mechanical properties are easily affected by water content. In this study, uniaxial compression, Brazilian test, and a double-sided shear test were performed on samples of loess with different water contents. The influence of water content on the mechanical properties of loess has been thoroughly investigated. The results demonstrate a clear linear relationship between the reduction in mechanical characteristics of the loess samples with increasing water content, including compressive strength, deformation modulus, tensile strength, shear strength, cohesion, and internal friction angle. Three failure types will occur for loess samples in the uniaxial compression test as the water content increases: tensile failure, shear failure with bulging, and conical failure with general thickening. In the shear test, the general expression of the shear strength of loess samples is obtained with water content as the independent variable. Finally, a deterioration coefficient K is derived based on the strength parameters of loess samples and can be used to describe the sensitivity to water content. Shear strength is more susceptible to variations in water content than compressive and tensile strength.