Hydraulic Behavior of Collapsible Compacted Gneiss Soil
Hydraulic Behavior of Collapsible Compacted Gneiss Soil
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DOI：
10.1061/(asce)1090-0241(2005)131:10(1264
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发表时间：
2005-10
影响因子：
3.9
通讯作者：
J. H. Pereira;D. Fredlund;M. C. Neto;G. Gitirana
中科院分区：
文献类型：
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作者：
J. H. Pereira;D. Fredlund;M. C. Neto;G. Gitirana
利用可独立控制净应力和基质吸力的三轴渗透仪系统，研究了在产生湿陷特性的条件下压实的残余片麻岩土的水力特性。不同但恒定荷载下的湿润路径被用来反映与坍塌的土石坝相关的现场条件。实验结果表明，不同的应力路径产生不同的体积塌陷量和不同的渗透系数变化，在相对较大的基质吸力下，渗透系数的变化主要受饱和度增加的影响。然而，随着土体接近饱和，渗透系数变得依赖于孔隙比和净平均应力，且饱和渗透系数在较大的塌陷量时减小。结果还表明，封闭在土壤空隙中的空气可能会显著降低渗透系数。在最佳拟合分析的基础上，提出了考虑净平均应力变化的渗透系数本构关系。
The hydraulic behavior of a residual gneiss soil compacted at conditions that produce collapsible characteristics was studied using a triaxial permeameter system that allows independent control of net stresses and matric suction. Wetting paths under differing but constant loads were utilized to reflect field conditions associated with a collapsing soil earth fill dam. The experimental results showed that different stress paths produce different amounts of volumetric collapse and distinct variations in the coefficient of permeability, which at relatively high matric suctions was mainly affected by the increase in degree of saturation. However, as the soil approached saturation, the coefficient of permeability became dependent on void ratio and net mean stress, with the saturated coefficient of permeability being reduced at larger amounts of collapse. The results also suggested that entrapped air in the soil voids may produce a significant reduction in the coefficient of permeability. A constitutive relationship for the coefficient of permeability that takes net mean stress changes into account was proposed based on best-fit analyses.