A METHOD FOR THE STATISTICAL EVALUATION OF SOIL RESISTIVITY FROM TEST DATA

Operational Safety Dept., National Center for nuclear safety

One major factor in the design of earth electrodes is the soil resistivity. This

paper is based on experience obtained at sites with high soil resistivity

variations. Many test measurements have been made to study the effect of

horizontal variations in soil resistivity at several selected locations at Inshas

area. The method is also applicable to soils with arbitrary soil resistivity

variations with depth. With such variations in the measured values, the question

then arises as to the correct value to be taken for the design. The paper presents

a methodology for the statistical estimation of soil resistivity from any test data

and computation of error bounds of the estimates in statistical terms. Actual test

field measurements of soil resistivity have been used as an application. The

bounds shown indicate the wide variability of soil resistivity.