FIG. 1 Graphical depiction of spectral-induced polarization measurements: ( A ) direct current resistivity where phase = 0 ; ( B ) low-frequency alternating current where phase ≠ 0 ; ( C ) typical complex electrical resistivity results reporting amplitude and phase. More about this image found in Graphical depiction of spectral-induced polarization measurements: ( A ) di...

FIG. 2 Specimen grain size distributions. The coarse-grained specimens are ballast fouling materials and therefore contain materials passing the 3/8 sieves. The fine-grained specimens include a manufactured clay that is classified as CL and two field-retrieved specimens with low and high plasticit... More about this image found in Specimen grain size distributions. The coarse-grained specimens are ballast...

FIG. 3 Complex electrical resistivity resting with agar experimental setup: ( A ) photo of compacted CH specimen at 13 % saturation; ( B ) simplified schematic. More about this image found in Complex electrical resistivity resting with agar experimental setup: ( A ) ...

FIG. 4 Experimental setup calibration evaluating the effects of agar on water and saturated sand. Water tests are also compared to water theory for calibration measurements to determine phase errors with frequency. More about this image found in Experimental setup calibration evaluating the effects of agar on water and ...