Abstract:

Loess structure is an important physical property, which influences mechanical properties of loess with its particle size, density and humidity. Based on the structure potential of loess released by loading, remolding and saturating, the unconfined compressive strength of intact, remolded and saturated loess were measured by uniaxial compression test; and the structural index of loess was defined by comparing the stability and changeability of loess structure which determined respectively by the ratio of confined compression strength of loess and remolding soil and the ratio of confined compressive strength of saturating loess and loess. Through the unconfined uniaxial compression test of four kinds of loess adopted from different sites, the unconfined uniaxial compression stress-strain curves of intact, remolded and saturated loesses with different water contents were tested to reflect the uniaxial compression stress-strain property, as well as the law of unconfined compressive strength and loess structural index changing with the water content was analyzed for different kinds of loesses. When the particle size, density and humidity of loess being similar, the greater the structure index of loess, the smaller the compressibility and the greater the shear strength of loess. So the structure Index structure together with the particle size, density and humidity can be used to describe reasonably the fundamental physico-mechanical properties of intact soils.

Key words: loess, structure, structure index, uniaxial compressive strength