| Natural site soils and remolded soils are often in the initial anisotropic stress state. During the excavation and backfill of the foundation pit and the construction and use of the structures, the change in the magnitude and direction of principal stress in the soil also induced anisotropy of the soil, thereby affecting the deformation and strength characteristics of the soil. Because the soil’s structure is broken, scattered and anisotropic, the deformation under load will become more complicated while the soil suffers complex stress path. It has always attracted scholars’attention for past decades that soils’ anisotropic deformation and deformation strength in complex stresses state.The soils in thesis are silty sediments and taken from Yellow River Delta in the Dongying city, Shandong province,then they are made into remolded samples with different initial water contents. The experiments apparatus is soil static and dynamic universal tri-axial and torsional shear apparatus developed by DUT. On the basis of test results, discuss the influences of initial water contents to the stresses increments-strain relation, orientation of principle stress and its relative variable characters of remolded saturated soils. The thesis researches anisotropy of the samples made in lab. The research in thesis is discussed.The static torsional shearing tests under different kinds of initial principal stress directions were performed on remolding saturated samples with3initial sampling water contents respectively. It is shown in results that the initial sampling water content had a remarkable influence on initial anisotropic behavior. The relation curve was asymmetry while the initial water content was0%. When the initial water content was10%, the stress increment-strain curve was symmetry. Under the same condition, the higher the initial sampling water content is, the less obviously the anisotropic behavior is. The difference between the strain path and the stress path was obvious. In the strain paths during the shear test it was seen that the strain paths were significantly fixed angle ray distribution, not as the same as the stress path. Initial water content had an influence on the development patterns of the strain paths. Initial water content had a influence on the variation trend between the principal stress direction and the principal strain direction, the higher the initial sampling water content is, the faster rate the initial strain direction changes.It is shown in tests results that the initial water contents have some influence in development tendency of non-coaxial phenomenon for stress and its increments. While the water content is zero w0=0%, the development tendency of changes slowly, else while w0=10%the development tendency receded in the initial time, the direction of strain increment parallels with stress. There is influence on the samples with different initial water contents non-coaxial phenomenon varying tendency, but is no effect on the non-coaxial phenomenon with shearing tests in angle α=30°in the condition of trial-direction non-settlement.Finally, the dynamic cyclic torsional shearing tests under3kinds of initial principal stress directions were performed on remolding saturated samples with2initial sampling water contents respectively. The result shows that:The initial principal stress direction and the initial water content have different influences on the relation curve of strains-normalized cycle-index ratio. The change of the strains in different directions was with ratio of number of cycles. N/Nf are dependent on initial water content; The changes of the principal strain directions and the changes of the principal stress directions with different water content are dissimilar; the remolding saturated samples shows remarkable non-coaxial phenomenon, the initial principal stress direction has no effect to the non-coaxial phenomenon, and the non-coaxial character is closely related to the initial water content. |
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