Hydraulic Conductivity of Noncohesive Soils

On the basis of a stochastic theory for the void‐size distribution in noncohesive soils and similar granular materials presented in a companion paper, equations for representative grain sizes in the two terms of the Kozeny‐Carman equation are derived. The equations are valid only for homogenous soils having a high degree of dehsification and a grain structure without loose grains. The pore velocity is assumed to be constant everywhere in the void space, and the hydraulic gradient is calculated by means of averaging local hydraulic gradients over the void space. The local hydraulic gradients are assumed to be given by a Kozeny‐Carman equation, with the local mean void chord length as pore diameter. Results from large‐scale permeameter tests on gravel and crushed rock support the derived equations and are the basis for evaluation of numerical coefficients.