Soil Consistency and Swell Potential Using Static Cone Penetration Machines

The use of static cone penetration test (CTP) as a site investigation tool for classifying potentially expansive soil has been outlined. The objective is to find a field a field method for classification of expansive soils. Four swell potential zones were identified in a plot of qc (cone resistance) versus fs (skin) friction. These potential zones are: non-expansive, low to medium, high and very high swell potential zones.
Ranges of fs and Rf= (fs/qc)x 100), termed friction ratio) that define the bounderies between these zones were also given.
In addition, the cone resistance qc was related to the relative consistency, Cr of the penetrated soil. A good correlation is found to exist between these two parameters. Again, limits of cone resistance values were obtained to enable estimates of the consistency of the soil.