广吸力范围内非饱和粉土动力变形特性

以非饱和粉土为研究对象,利用饱和盐溶液蒸汽平衡法和吸力可控的动三轴仪进行动力变形试验,得到了广吸力范围内非饱和粉土试样在净围压和吸力基本不变条件下的骨架曲线、动弹性模量和阻尼比,研究了吸力对非饱和粉土动力变形特性的影响。结果表明,在同一净围压下,非饱和粉土试样的骨架曲线和动弹性模量随着吸力增大而提高,而阻尼比随着吸力增大而减小。此外,随着试样的水力状态从边界效应区到过渡区再到残余区的变化,非饱和粉土试样的骨架曲线和动弹性模量的提高幅度逐渐减小,而阻尼比减小的趋势显著,动弹性模量随应变的衰减率随着吸力的增大而减小。

Dynamic deformation characteristics of unsaturated silt over a wide suction range

By using a suction-controllable dynamic triaxial testing apparatus, a series of dynamic deformation tests are carried out on a unsaturated silt subjected to wide suctions imposed by the axial translation technique and vapor equilibrium method with saturated salt solution. The skeleton curves, dynamic elastic moduli and damping ratios are obtained over a wide suction range under almost constant net confining stress and suction. The effect of suction on dynamic deformation characteristics of unsaturated silt is studied. The test results show that at the same net confining pressure, the skeleton curves and dynamic elastic moduli increase with increasing suction, but the damping ratios decrease with increasing suction. As the hydraulic state of specimens changes from the boundary effect zone to the transition zone and then to the residual zone, the increase rates in the skeleton curves and dynamic elastic moduli decrease gradually, the decrease rate in the damping ratios is still obvious, and the decay rate of the dynamic elastic moduli with strain decreases with the increasing suction.