杭州市粉土的各向异性室内试验研究

Experiment on the anisotropy of Hangzhou silt

工程现场取得杭州市典型的粉土土样,用击实的方法制备重塑粉土试样,按与水平沉积面成不同夹角方向切取土样,进行标准固结试验、直剪快剪及渗透试验,从土体压缩变形、强度和渗透性能三个方面,对重塑粉土各向异性特性进行研究.结果表明:重塑粉土在变形、强度及渗透性三方面都表现出不同程度的、相互关联的各向异性,45°取样方向试样的压缩系数比0°和90°取样方向试样小,其强度与渗透系数也比其它两个方向小.因此,进行粉土地基的变形分析和强度计算时,应考虑各向异性的影响.研究结果对复杂加荷条件下粉土地基的工程实践有一定的参考意义.

Silt soil was taken from a construction field in Hangzhou and remoulded in laboratory by compaction method.For the analysis of anisotropic character of silt,samples were prepared by cutting through the compacted soil at different angle to the horizontal surface and tested in laboratory by consolidation test,direct shear test and permeability test.The results show that compacted silt exhibits anisotropic behaviour in all the three tests and the anisotropy characters are related in compressibility,strength and permeability.The coefficient of compressibility,the direct shear strength and the permeability coefficient of silt are all smaller at direction angle of 45°than at the other two directions of 0°and 90°.This can offer a reference to the analysis of silt ground deformation and bearing capacity,especially under complex loading conditions.