Numerical Simulation of Water Movement in the Suction Equalization of a Thermal Conductivity Sensor

Abstract

Abstract Laboratory and field measurements of soil suction using a thermal conductivity soil suction sensor involves installing the sensors into a soil mass. The sensors may be installed either in an initially wet or an initially dry state. In order to ensure a reliable suction measurement, it is important that the sensor reach suction equalization with the surrounding soil. The results of a numerical study have shown that, in most cases, the equalization time required for an initially dry sensor is less than the equalization time for an initially wet sensor. This difference is mainly due to the unsaturated zone that develops on the boundary of the initially wet sensor at the beginning of the drying process. The results of the numerical simulation have been substantiated by laboratory suction measurements.