Stress clay contamination

The PF technology also has several potential limitations. Fractures do not always propagate in the direction or to the distances expected. Fractures may open new pathways for the unwanted spread of contaminants. Pockets of low permeability may remain after fracturing. Surface heave and stress resulting from the process can create hazards for buildings or other structures at a site. If the moisture content of the contaminated media is not controlled, the formation may swell and close the fractures. PF is not applicable at sites with high natural permeabilities. Fractures will close in soils with low clay content. In addition, PF should not be used in areas of high seismic activity. 

Hueckel, T. 1997. Chemo-plasticity of clays subjected to stress and flow of a single contaminant. Int. J. Num. Anal. Meth. Geom. 21 pp. 43-72. 

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