Calculations for individual anode resistances or the resistance of a composite group of anodes, termed “a ground-bed,” are practical where soil resistivity changes are relatively gradual, both in respect to horizontal distance and depth; also where the symmetry of the ground-bed pattern can be maintained.
Conditions are encountered where soil resistivity changes are abrupt with respect to horizontal and vertical. These conditions result in the adoption of devious ground-bed patterns, irregular spacing and depth of anodes to permit anode placement in lowest resistivity soil. Deviation of pattern complicates calculations; variations in depth adds to this and abrupt soil resistivity changes introduce qualifying factors beyond practical use.
Such erratic conditions are most frequently encountered where soil formations are composed of successive thin stratum and these conditions may be further complicated by previous erosion, followed by succeeding sedimentary deposits.
Soil resistivity variations encountered during investigations for eleven ground-bed locations (totalling 66 anodes)...
