利用空心圆柱扭剪仪对含非塑性细粒的饱和砂土进行单调加载和循环扭剪试验，研究了不同细粒含量饱和砂土的液化特性。试验结果表明：（1）最大孔隙比与最小孔隙比均随着细粒含量的增加呈先减小后增大的趋势，分别在20%和40%时达到最小。（2）细粒含量从0%增加到20%，体积应变逐渐增加；细粒含量从20%增加到40%时，体积应变逐渐减小；之后随着细粒含量从40%增加到60%，体积应变再次增大；细粒含量超过60%以后，体积应变再次递减。（3）随着细粒含量的增加，土样的峰值强度随之降低，应力-应变关系从应变硬化特征发展为理想的弹塑性。相变角在细粒含量为30%时达到最小值。（4）细粒含量越大，达到液化所需的循环次数越小，液化时的应变越小。（5）抗液化强度曲线与抗液化应力比的变化趋势一致，在小于界限细粒含量（30%）时，随着细粒含量的增加而减小。在界限细粒含量附近（30%～50%）时，随着细粒含量的增加而增大。在细粒含量增加到60%时出现明显的骤减，之后再次随着细粒含量的增加而增大。界限细粒含量在40%左右。

Laboratory tests on the liquefaction properties of saturated sand with different contents of non-plastic fines were performed by a hollow cylinder apparatus. Results show that: (1) The maximum void ratio emax and minimum void ratio emin decrease and then increase, reaching minimum at 20% and 40% respectively. (2) As fines content increases from 0% to 20%, volumetric strain increases. When fines content increases from 20% to 40%, volumetric strain decreases. Afterwards, volumetric strain increases again when fines contents are between 40% and 60%. Finally, volumetric strain decreases when fines content is more than 60%. (3) The sand with larger fines content has smaller peak strength. Stress-strain curves transform from strain-hardening behavior to a perfect elastic- plastic stress-strain behavior. The phase transformation angle reaches minimum at fines content of 30%. (4) The larger fines content is, the smaller number of cycles and strain to liquefaction are. (5) Liquefaction resistance curve and cyclic resistance ratio have the same trend. They decrease when fines content increases from 0% to the threshold fines content of 30%, and increase when fines content increases from 30% to 50%, and decrease sharply at fines content of 60%, and then increase with increasing fines content. The threshold fines content is about 40%.