The Study On Loess Structure And It’s Strength And Deformation Characters

Natural loess has remarkable structural characteristic.Loess structure is changing constantly under immersion and loading.It is not in accordance with actual working condition to study the natural structure of loess only.For loess engineering with large disturbance,if the study on loess strength and deformation is based on natural structure in the design process,it will undoubtedly leave large potential safety hazard;if the research is reconsidered according to the changed structure in the development of plastic deformation under moistening and shear,it has theoretical significance and practical value for revealing the strength and deformation characteristics of loess.Based on triaxial isotropic compression test,shear loading and unloading test and uniaxial compression test after unloading on undisturbed loess,remolded loess and saturated loess,the structural change law of loess under triaxial shear plastic deformation is analyzed by using structural index.The influence of water content,consolidation confining pressure and plastic strain on change law of structural quantitative index is revealed.Then,the relationship between structure and comprehensive plastic strain and the influence of water content and consolidation confining pressure on the stress-strain relationship of loess are established.The evolution of loess microstructure under consolidation,remolding and saturation is measured by micro-CT test,and the mechanical behavior of displacement and deformation of loess particle is verified.What’s more,the effects of water content and consolidation confining pressure on loess structural index,uniaxial compressive strength and deformation under plastic deformation are studied.The research results have gained new understandin g.