吹填人工岛地基钙质粉土夹层的渗透特性研究

发布时间：2018-05-03 08:06

本文选题：钙质粉土 + 渗透系数　；参考：《岩土力学》2017年11期

【摘要】：南海吹填钙质土地基中含有多层粒径小于0.075 mm的细颗粒钙质粉土夹层,这些粉土夹层的渗透性对人工岛地下淡水的形成具有重要影响。通过室内变水头试验研究了钙质粉土渗透系数与干密度、初始含水率之间的相关性,论证了Samarasinghe与Mesri公式在计算钙质粉土渗透系数上的可靠性;通过静态氮吸附试验对渗透试验前、后钙质粉土的孔径变化特征进行了分析。研究结果表明:钙质粉土的渗透系数在初始含水率相同时随着干密度的增大而减小,在干密度相同时随着初始含水率的增大而增大,且在饱和时渗透系数达到最大;Samarasinghe与Mesri公式对钙质粉土渗透系数的计算具有较高精度;钙质粉土为大孔材料,渗流作用下使更多的微孔和介孔转变为大孔,孔隙类型以一端开口的均匀圆筒形孔为主。研究成果可为南海的人工吹填岛地下水渗流场的计算分析提供科学依据。
[Abstract]:There are many layers of fine grained calcareous silt intercalations with diameter less than 0.075 mm in the ground filled with calcium in the South China Sea. The permeability of these silt interlayers has an important effect on the formation of underground fresh water on artificial islands. The correlation between permeability coefficient, dry density and initial moisture content of calcareous silt was studied by laboratory water head test, and the reliability of Samarasinghe and Mesri formula in calculating permeability coefficient of calcareous silt was demonstrated. The pore size variation characteristics of calcareous silt before and after permeation test were analyzed by static nitrogen adsorption test. The results show that the permeability coefficient of calcareous silty soil decreases with the increase of dry density when the initial moisture content is the same, and increases with the increase of initial moisture content at the same dry density. The permeability coefficient of calcareous silt reached the maximum when saturated with the formula of Samarasinghe and Mesri, and the calculation of permeability coefficient of calcareous silt was highly accurate, and that of calcareous silt was macroporous material, and more micropores and mesoporous cells were transformed into macropores under the action of percolation. The pore type is the uniform cylindrical pore with one end opening. The research results can provide scientific basis for the calculation and analysis of groundwater seepage field in artificial filling islands in the South China Sea.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;中国科学院大学;
【基金】：科技部973计划课题(No.2013CB956104) 自然科学基金项目(No.41572297,No.41572304,No.41372318) 国家科技支撑计划项目(No.2014BAC01B01)~~
【分类号】：TU411

【相似文献】