Whatever the causes of the contamination variability, settlements associated with the infiltration would also be variable, favoring the occurence of differential settlements.
b. Percussion Borings
For the area of the anodization, where a greater number of percussion borings has been executed, the results of SPT values are plotted with depth in figure 2, together with data obtained from borings prior to industry installation and from a single boring (SPB-1) carried out recently in a nearby non-contaminated area.
The results indicate that SPT values in acid or basic contamined soil, independently of the degree of contamination are generally lower than the non-contaminated soil values down to a depth of about 6,0 m. This suggests a reduction in bearing capacity in this zone, associated with reactivity to the percolating fluids.