INVESTIGATION OF THE RELATIONSHIP BETWEEN HYDRAULIC CONDUCTIVIY AND PHYSICAL PROPERTIES OF FINE GRAINED SOILS

Hydraulic conductivity has been used for engineering geology related projects since last decades of 19th century in order to estimate the ability of soils to transportation of water through soil particles. Constant and falling head test are widely used to directly measure the hydraulic conductivity values ofsoil samples based on their grain size distributions. In order to perform constant and falling head test, field investigation and undisturbed sampling works should be performed. In order to overcome the time consuming and difficult processes of field works and undisturbed sampling, numerous empirical equations have previously proposed based on physical properties of soil materials to estimate the hydraulic conductivity of soil samples. Most of these equations are based on void ratio, porosity, specific surface area, Atterberg limits and some parameters related with grain size distribution. These equations are not applicable to estimate particularly hydraulic conductivity of fine grained soils due to limitations regarding with physical properties of soil samples. In this study, in order to describe the relationship between hydraulic conductivity and physical properties of soils, tests including falling head methods and measurements of grain size distributions and Atterberg limits were performed on 15 soil samples which collected from different locations during field studies. Considering the results obtained from laboratory test, it can be concluded that there is statistically significant relationship (R2=0.94) between hydraulic conductivity and grain size index values of samples which contains gravel size materials lower than %10