Identifying dispersive soils by modification of chemical criterion, validated based on data from Northwest and Central Iran.

There are different methods to identify dispersive soil and several studies have attempted to produce a reliable method for this goal. Some studies have shown incompatibility between field observations and laboratory test results, especially for a chemical criterion. In this study, the dispersivity potential of 328 soil samples having a broad distribution in Iran was evaluated using pinhole and chemical tests in saturated soil extract. The compatibility of the Sherard chemical criterion and pinhole test results was first evaluated. Then, a modified criterion in the general form of the Sherard chemical criterion was suggested based on the pinhole test results to evaluate the dispersivity potential of the clay soil. The results show 44% compatibility between the Sherard chemical criterion and pinhole tests results for the studied samples while the proposed criterion shows 67% of compatibility. [ABSTRACT FROM AUTHOR]