## 5 Conclusions  
(1) The arrangement of soil particles and the intergranular associations of the soil skeletal structure are stabilized against external loads and variables against damage. Based on the ratio of undisturbed soil shear strength and saturated remodeled soil shear strength, the stabilizability and variability of loess structures are integrated. The established structural parameter mainly includes immersion sensitivity and disturbance sensitivity, revealing the change rule of immersion sensitivity and disturbance sensitivity. The soaking sensitivity of loess varies greatly with natural moisture content, while the disturbance sensitivity varies less with natural moisture content, reflecting the water sensitivity of loess. (2) The structural characterization parameters given in this paper are defined in terms of shear strengths of undisturbed soil and remodeled saturated soils, which at once releases the integrated structural potential of the soil and reflects the strength characteristics and essential properties of the soil. The structural parameters of loess gradually decrease with the increase of confining pressure (consolidation pressure), moisture content, and dry density. The quantitative analysis of the influencing factors of the structural parameters led to the conclusion that the moisture content has the greatest influence on the structural properties, the dry density has the least influence, and the degree of influence of the peripheral pressure is in the middle. (3) The effects of grain size, density, and moisture on the structural properties of loess were revealed by analyzing the relationships between the structural property parameters and the ratio of dry density to porosity ratio, between the structural property parameters and the difference between the plastic limit and moisture content, between the structural property parameters and the liquid and plastic limits, and between the structural property parameters and the liquidity index. It is shown that the structural property decreases with the increase of the ratio of dry density and porosity with the increase of the difference between plastic limit and moisture content; increases with the increase of the plastic limit; and, at low moisture content, shows a peak variation curve relationship with the increase of the liquid limit. The correlation between them shows that the new structural parameters of loess can comprehensively reflect the physical properties, such as particle size, density and moisture; the discrete nature of the different correlations between them indicates the structural differences in the arrangement of soil particles in the soil skeleton and the intergranular association characteristics. (4) A physical characterization measure that integrates particle size, density, and moisture has been established by the liquidity index, dry density ratio, and pore ratio. Under the condition of approximate consistency of dry density, there is a monotonically varying relationship between the parameters of structural properties of loess and the integrated physical characteristic quantities. This indicates both that the liquid-plastic limit, moisture content, dry density, and pore ratio of loess, as reflected by grain size, density, and moisture, have a significant effect on its structural properties, and that loess with the same degree of conformation may have different indices of grain size, density, and moisture properties. (5) The particle size, density, moisture content, and structural properties of soils are inherent indicators of their material composition and state characteristics, which are used to characterize the mechanical properties of soils and their patterns of change. Structural parameters are quantitative indicators of the structural properties of the soil body, which are related not only to the composition and state of the soil material in terms of grain size, density, and moisture, but also to the characteristics of the spatial arrangement of soil particles in the soil skeleton structure and intergranular associations.