中文摘要：

使用非饱和土动三轴试验仪,对非饱和粉土进行动力强度试验,探讨了饱和度、动应力比及固结围压对非饱和粉土动力强度特性、液化特性及孔压特性的影响。试验结果表明：（1）非饱和粉土的动强度随饱和度的增加而下降,在相同动剪应力比下饱和度与液化振次在半对数坐标上成线性关系;（2）非饱和粉土的液化与不液化的临界曲线近似成S型,非饱和粉土的抗液化能力随饱和度增大而降低,当饱和度小于60%时,土样不会液化;（3）非饱和粉土的动孔压随振次增大而增长,孔压的增长呈现出三段式的模式。

英文摘要：

The dynamic strength characteristics of unsaturated silt have been studied by using a dynamic triaxial testing apparatus for unsaturated soils.Some test results have been obtained,including the characteristics of dynamic strength,liquefaction and pore-water pressure under the conditions of different saturation degrees,shear stress ratios and cell pressures respectively.The test results show that（1）the dynamic strength decreases with increasing of saturation degree;the relationship between the saturation degree and cycle number is linear in the semi-logarithmic coordinates at failure under the same shear ratio;（2）the liquefaction critical curve of unsaturated silt approximates to be the S-shape;the liquefaction resistance is decreasing with the increasing of saturation degree;the liquefaction is no longer taken place when the saturation degree is less than 60%;（3）the pore-water pressure increases in a way of 3-stage with the increase of the cycle number.