浸水大堤填土饱和度修正意义及工程运用

Significance and Application of Revising Saturate Degree of Cohesive Earth Fill of Inundated Embankment

饱和度指标可通过含水率换算获得;但对长期浸水的大堤而言,由于采用烘干法试验测得的试样的含水率普遍偏高,因此直接计算的饱和度值普遍偏大。根据土、水相互作用性质,分析土颗粒周围结合水分布特点,指出浸水大堤填土试样饱和度偏高的原因在于烘干试验中有部分弱结合水逸出,并且这部分弱结合水被计入到重力水中。根据经典土力学理论,建立完全饱和土的二相体系模型,对饱和度与弱结合水含量间的关系进行定量分析,并把所得的结论用于工程实践。

Degree of saturation of soil can be calculated by testing indices such as water content, unit weight and specific gravity. In practice, research indicates that saturation degrees of cohesive fill of inundated embankment are usually more than its true values. This paper discusses the distribution of gravitational water and loose bound water around the soil pellet and analyzes the reaction between bound water and soil granules. Results indicate that it is the loose bound water vaporized from the soil that causes this error. Based on the soil mechanics theory, the sketch model of two phases of full saturated soil is established and the formula is deduced. Research shows that there is a distinct linear relationship between degree of saturation and loose bound water evaporated from the full saturated fills.