Amelioration of Tunnelling Susceptible Soils in the Hunter Valley, New South Wales, by Modification of Clay Double-Layer Interactions
SourceThe resultant force between van der Waals attraction and net free energy of interacting clay double layers has been calculated for a typical tunnelling susceptible soil in the Hunter Valley, N. S. W., Australia. Double-layer theory accounts adequately for the instability of this soil and for its response to wetting.
Double-layer theory has been used to derive a sodium absorption ratio versus sum of cations stability diagram for this soil specimen. The slope of the line separating flocculation and dispersion approached seven.
The soil was prepared with sodium and calcium chloride salts at different concentrations at and around the threshold of flocculation as predicted by double-layer theory. Aggregate stability, dispersal index, and behavior in model dams confirmed the predicted behavior