Abstract

Interpretation and reliability of in situ tests, such as cone penetration, can be improved if in situ moisture content and density can be measured without affecting the speed of site investigation significantly. This paper describes the principle and technique of determining moisture content with a penetrometer that can measure the dielectric constant (specific inductive capacitance) of soils. Effects of various factors, such as salt content of water, on the measured parameter are discussed with special reference to frequency of the measuring bridge. This study shows that it is possible to determine the in situ moisture content of soils from measurements conducted at very high frequencies. This method presents particular promise because the moisture content versus capacitance relationship has been found to be practically independent of soil type.

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