Practical pedotransfer functions for estimating the saturated hydraulic conductivity

The saturated hydraulic conductivity k is one of the most important and widely used geotechnical parameters, commonly involved in a diversity of applications. The value of k depends on many factors, which can be divided into three classes: properties of the fluid, pore size distribution, and characteristics of the solid surfaces. Because the latter two are not necessarily constant within a given deposit, the hydraulic conductivity may vary significantly in space. Engineers and scientists need indications about how changing factors may affect the actual k value. In this paper, the authors propose some simple expressions, based on pedologic properties, to estimate the value of k. Using experimental results of their own and taken from the literature, it is shown that the proposed pedotransfer functions can be used for quickly estimating the k value for granular and plastic cohesive soils. Such expressions can be employed, with a useful chart format, for the preliminary design phase of a project, and also for estimating the range of k values to be anticipated within a given deposit.