选取广东粉土质砂（SM）为研究对象，在一系列室内试验基础上，研究该土的渗透、变形和强度等力学特性，并探讨粉土质砂的应力应变关系和邓肯模型参数。试验成果表明：粉土质砂在压实和胶结程度高的条件下，其渗透性较低，压缩性中等，抗剪强度极高；其应力-应变关系表现有明显峰值和应变软化特征，在剪应力作用下土体开始表现为剪缩特性，当变形达到一定值后，表现出剪胀特性；此外，土体的本构关系能较好地采用邓肯模型来反映。研究结果为解决粉土质砂的工程问题提供了很好的基础和依据。

Based on laboratory tests on the silty sand in Guangdong, we researched on the permeability, deformation and strength of the silty sand, and discussed its stress-strain relationship and parameters of Duncan model. Results show that the soil is of low permeability and medium compression and extremely high shear strength under a high degree of compaction and cementation. The stress attained an obvious peak value and then decreased sharply with the increasing strain. Under shear stresses, the soil exhibited shear contraction, and then when the deformation increased to a certain value, the soil displayed shear dilatation features. What’s more, Duncan model can be used to describe the constitutive relation of the soil. The research results will provide foundation and basis to solve engineering problems of silty sand.