The saturated hydraulic conductivity of soils is a critical concept employed in basic calculation in the geotechnical engineering field. The Kozeny–Carman equation, as a well-known relationship between hydraulic conductivity and the properties of soils, is considered to apply to sands but not to clays. To solve this problem, a new formula was established based on Hagen–Poiseuille's law. To explain the influence on the seepage channel surface caused by the interaction of soil particles and partially viscous fluid, the surface area ratio was introduced. A modified framework for determining the hydraulic radius was also proposed. Next, the relationship between the effective void ratio and the total void ratio was established for deriving the correlation of hydraulic conductivity and total void ratio. The improved equation was validated using abundant experimental results from clays, silts, and sands. According to the results, the accuracies of the proposed model with two fitted multipliers for clays, silts, and sands are 94.6, 96.6, and 100%, respectively, but with only one fitted parameter, the accuracies are 97.1, 91.5, and 100%, respectively. The proposed model can be considered to have a satisfactory capability to predict hydraulic conductivity for a wide variety of soils, ranging from clays to sands.

土壤的饱和导水率是岩土工程领域基础计算中使用的一个关键概念。Kozeny-Carman 方程作为水力传导率和土壤性质之间的众所周知的关系，被认为适用于沙子而不适用于粘土。为了解决这个问题，根据哈根-泊肃叶定律建立了一个新的公式。为了解释土壤颗粒与部分粘性流体的相互作用对渗流通道表面的影响，引入了表面积比。还提出了一种用于确定水力半径的修改框架。接下来，建立有效孔隙率与总孔隙率之间的关系，以推导出水力传导率与总孔隙率的相关性。使用粘土、粉砂和沙子的大量实验结果验证了改进的方程。结果表明，该模型在粘土、粉砂和砂土两个拟合乘数下的精度分别为94.6、96.6和100%，但只有一个拟合参数时，精度分别为97.1、91.5和100% ， 分别。可以认为所提出的模型具有令人满意的能力来预测从粘土到沙子的各种土壤的水力传导率。