南水北调工程粘土岩基本物理性质试验研究

Experimental Study on Basic Physical Properties of Clay Rock in South-to-North Water Diversion Project

粘土岩是南水北调中线工程总干渠潞王坟膨胀岩试验段具有代表性的膨胀岩之一。通过颗粒分析试验、击实试验、膨胀性试验和渗透试验来了解其基本物理性质,结果表明:①粘土岩的颗粒组成以粉粒、粘粒和胶粒为主,含有少量砂粒,级配一般;轻型击实、干土法制样时,粘土岩最优含水率为25.9%,最大干密度为1.56 g/cm3。②粘土岩的自由膨胀率为68%～70%,具有中等膨胀潜势;其无荷膨胀率、膨胀力均随干密度的增加而增加,但干密度达到1.60 g/cm3后,粘土岩的无荷膨胀率和膨胀力增幅均有不同程度的减缓。③粘土岩原状样和重塑样的渗透系数随着干密度的增大而减小。

Clay rock is one of the most representative swelling rocks in Luwangfen expansion rock experimental section of the main canal in central line project of South-to-North water diversion.Through particle analysis test,compaction test,expandability test and permeability test,its basic physical properties are studied.The result shows that clay rock is mainly composed of silt,clay and colloidal particle,containing a small amount of sand with general grading.When produced using dry soil by light compaction,the optimal water content of clay rock is 25.9% and maximum dry density is 1.56g/cm3.In addition,free swelling ratio of clay rock is 68%～70%,with moderate expansion potentiality.Its no-load expansion rate and expansive power increase with the increase of dry density.But when dry density reaches 1.60g/cm3,the increase of its no-load expansion rate and expansive power slows down to different extents.Moreover,permeability coefficient of original sample and remodeling sample of clay rock decreases with the increase of dry density.