Abstract
The apparent dielectric constant and the resistivity of Toyoura sand, Kasama decomposed granite soil and Sakan sand were measured associated with a wide variety of the volumetric water content and the saturation degree from saturated state to dried state. The sand specimens were saturated by using the solutions with different NaCl concentrations. The apparent dielectric constant at the saturated state was nearly independent of the resistivity of pore water at the lower NaCl concentration range (≤2, 000ppm), on the contrary, the apparent dielectric constant notably increased at the higher NaCl concentration range (≥5, 000ppm). Consequently, in the case of determination of the volumetric water content of sand with the higher salinity by using measured value of apparent dielectric constant, it is essential to obtain the calibration curves at the same salinity condition. In addition, the apparent dielectric constant at the same NaCl concentration sensitively decreased with the decrease of volumetric water content, in the every sand. The determined relationships between the apparent dielectric constant and the volumetric water content of Kasama decomposed granite soil and Sakan sand were in agreement with the empirical equation presented by TOPP et al., however, that one of Toyoura sand differed from the empirical equation because an inhomogeneous distribution of the pore water occurred in the specimen. The resistivity of the sands at the same saturation degree sensitively decreased with the decrease of the resistivity of pore water. Further, the relationships between resistivity of Toyoura and Sakan sands at the saturated state and the resistivity of pore water were linear, but that one of Kasama composed granite soil was non-linear.
