Abstract
AbstractThe 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.
Highlights
Saturated hydraulic conductivity represents the ability of soils to transmit water under saturated conditions (Jabro ) and is related to the characteristics of both fluid and its transport medium (Najafzadeh et al )
The results show that the Kozeny–Carman equation can obtain ideal calculation results for sandy soil and silty clay
Data for saturated hydraulic conductivity measured with water as the permeant are included
Summary
Saturated hydraulic conductivity represents the ability of soils to transmit water under saturated conditions (Jabro ) and is related to the characteristics of both fluid and its transport medium (Najafzadeh et al ). The essential use of the Kozeny–Carman equation to predict the hydraulic conductivity of fine-grained soils is to propose a method to estimate an effective void ratio. The surface area loss due to the contact of soil particles was usually ignored when deducing the equation of the soil hydraulic conductivity, and the reduction in the surface area of the seepage pipes caused by contacts between particles was not considered It cannot really reflect the pore structure characteristics of clay. The fluid in contact with the inside surface of the pipe (r 1⁄4 R) has been shown to have zero velocity, which means that there is a part of the viscous water occupying the corresponding surface area of the soil particles. The effective void ratio and the ineffective void ratio can be computed as
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have