粗粒料的蠕变和湿化试验研究.pdf

长江科学院 硕士学位论文 粗粒料的蠕变和湿化试验研究 姓名：左永振 申请学位级别：硕士 专业：岩土工程 指导教师：程展林 20080601 摘 要 粗粒料作为高堆石坝的主要筑坝材料， 其蠕变和湿化力学特性是高堆石坝工 程中的重要研究课题本文依托大渡河双江口水电站 300m 级土质心墙堆石坝关 键技术研究项目，对粗粒料的蠕变和湿化特性进行了较为系统的研究，揭示了粗 粒料蠕变和湿化变形的规律 利用大型高压三轴仪对粗粒料的蠕变和湿化变形特性进行了系统的试验研 究首先进行了粗粒料的 K0状态压缩蠕变试验，认为压缩蠕变试验可以视为单 一应力水平的三轴蠕变试验，它不能反映应力水平对粗粒料蠕变的影响，进行粗 粒料的蠕变研究，宜采用三轴蠕变试验；进行的三轴蠕变试验研究揭示了粗粒料 蠕变的基本规律： 双江口堆石坝粗粒料的蠕变量与时间关系可以用幂函数准确表 达，其蠕变量符合九参数蠕变模型，验证了九参数模型的合理性；通过蠕变试验 后其级配曲线的分析， 发现蠕变过程中粗粒料的颗粒破碎和三轴剪切试验的颗粒 破碎量近似，并且认为粗粒料可能存在“最优颗粒分布形态”；通过玻璃球蠕变 试验和三轴剪切蠕变试验的对比分析， 认为蠕变过程中的颗粒破碎是影响其蠕变 参数的主要因素。

粗粒料湿化试验发现了粗粒料湿化变形的基本规律： 粗粒料的单线法和双线 法得到的湿化变形量差别较大，在对粗粒料的湿化变形进行研究时，应以单线法 为主；粗粒料的湿化轴向变形随湿化应力水平的增大而增大，并在湿化应力水平 0.7 附近出现拐点，在湿化应力水平 0.7 之后，湿化轴向变形随湿化应力水平的 增加而急速增大，而与围压的相关性不大；湿化体积应变随湿化应力水平和围压 的增加而增加，不在保持常数不变；提出了单线法经验公式，湿化轴向变形与湿 化应力水平的关系可以用指数型函数拟合， 湿化体积应变与湿化应力水平的关系 可以用线性函数拟合； 在试验基础上得到的经验公式基本上能反映粗粒料的湿化 变形特性 本文最后借助于岩土可视化技术， 揭示了粗粒料受力过程中试样内部颗粒的 变化规律：粗粒料的变形源于颗粒的位置调整；在某一宏观应变下，试样中颗粒 的平动和转动有很强的规律性，试验中各部位的颗粒位置调整的幅度差异较大， 相同部位不同颗粒的调整幅度也不同；相邻颗粒间的错动明显，并伴有一定的转 动；颗粒的转动方向与颗粒长轴的随机分布有关，转动量与相邻颗粒的错动大小 有关；颗粒的平动和转动与围压的关系不明确，只与轴向应变密切相关。

本文最后对全文的主要工作做了总结,对今后的研究工作进行了展望 关键词：堆石坝 粗粒料 蠕变 湿化 CT 组构 ABSTRACT 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, 。