Research On Creep Deformation And Wetting Deformation Of Coarse-Grained Materials

The coarse-grained materials is the main build material of the high rock-fill dam, its creep and wetting mechanics characteristic is the important research subjects on the high rock-fill dam project. This article depends on the Dadu River Shuangjiangkou power key technologies research project, has systematically researched the creep and wetting characteristic of coarse-grained materials, and disclosured the coarse-grained materials creep deformation and wetting deformation rule.Used the large-scale high-pressured triaxial instrument has conducted systematically test on the creep deformation and wetting deformation characteristic of coarse-grained materials. First has carried on the K0 condition compressive creep experiment, thought that the compressive creep experiment may regard as the sole stress level triaxial creep test, it cannot reflect the influence of stress level, so research the creep, it suitably uses the triaxial creep test. The triaxial creep test research disclosure the coarse-grained materials creep deformation basic rule: The creep deformation quantity and the time relationship of shuangjiangkou rock-fill dam's coarse-grained materials may use the power function to express accurately, its creep deformation quantity conforms to nine parameter creep model, and has confirmed nine parametric model rationality; After grading curve's analysis, discovers in the creep process the granule broken is approximate to the triaxial shear test, and thought that the coarse-grained materials possibly has"the most superior granule distributed shape"; Through the glass spherule creep test and the triaxial creep test's contrastive analysis, reveals the granule broken is the primary factor to affect the creep parameter.The coarse-grained materials wetting experiment, has discovered the wetting deformation basic rule: There is a big difference between wetting deformations obtained form the single law and double law, so when research the coarse-grained material's wetting deformation, should primarily used the single law; The coarse-grained material's wetting axial strain increases with the wetting stress level, and nearby 0.7 presents the inflection point, after wetting stress level 0.7, the wetting axial deformation increases rapidly with the wetting stress level increases, but there is no big different between the condition of difference confining pressure; The wetting volumetric strain increases along with the wetting stress level and confining pressure increases, does't maintain the constant; Proposed the single track law empirical formula, the relationship of wetting axial strain and the wetting stress level may use the exponential function to fit the regularity, the wetting volumetric strain and the wetting stress level's relationship may use the linear function to fit; The empirical formula which obtains form the experimental can basically reflect the coarse-grained material's wetting deformation characteristic.This article finally used the CT visualization technology, has revealed the granule movement rule in the stress process of the test specimen; The coarse-grained material's distortion stems from the granule position adjustment; Under some macroscopic strain, the granule's translation slip and the rotary movement have the very strong regularity, there is a big contrast between the difference spots, the same spot different granule's argument is also different; Neighboring intergranular's moving is obvious, and is accompanied by certain rotation; granule's rotation direction relate to the granule major axis random distribution, and rotation also relate to the neighboring granule's moving; The granule's translation slip and the rotary movement are not explicit to the confining pressure, and is only closely related with the axial strain.In the end of this paper, main ideas of this paper are concluded, furthermore, some question for future studies are put forward.