Porosity and permeability in ternary sediment mixtures

Area of Science:

• Geology
• Civil Engineering
• Environmental Science

Background:

• Accurate prediction of soil permeability and porosity is crucial for various engineering applications.
• Understanding the behavior of granular mixtures requires robust modeling techniques.
• Existing models may not fully capture the complexities of multi-component granular systems.

Purpose of the Study:

• To develop and validate models for predicting permeability (k) and porosity (φ) in three-component sand mixtures.
• To investigate the effectiveness of the Kozeny-Carman equation for such mixtures.
• To explore different modeling approaches for porosity and their impact on permeability predictions.

Main Methods:

• Systematic variation of volume fractions for fine, medium, and coarse sand components.
• Measurement of permeability (k) and porosity (φ) for each mixture.
• Application and adaptation of the Kozeny-Carman equation using a recursively averaged representative grain size parameter (d).
• Modeling porosity using linear interpolation with piecewise-planar models and evaluating the trade-off between accuracy and data requirements.

Main Results:

• The Kozeny-Carman equation, with a recursively averaged grain size parameter, effectively modeled permeability in the sand mixtures.
• Porosity was well-represented by linear interpolation with piecewise-planar models.
• The permeability model demonstrated higher sensitivity to the representative grain size (d) than to porosity (φ).
• The permeability model yielded consistent results whether using measured porosity or porosity values derived from the developed models.

Conclusions:

• A refined Kozeny-Carman approach provides a reliable method for predicting permeability in multi-component sand systems.
• Piecewise-planar models offer a flexible and accurate way to estimate porosity in granular mixtures.
• The developed models enhance the understanding and prediction of hydraulic properties in complex granular materials.