WATER PERMEABILITY-TESTING DEVICE, AND WATER PERMEABILITY-TESTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a water permeability-testing device and a water permeability-testing method, which can reduce the size of the device and easily perform installation work by confining ultrasonic wave in a hollow ultrasonic waveguide and propagating it.;SOLUTION: In a water permeability-testing device: water is stored in an ultrasonic waveguide 6 which is a hollow member whose one end is sealed and the another end is opened, and has an inner diameter equal to or less than four times a wavelength of an ultrasonic wave transmitted from an ultrasonic transmitting element provided in the interior on the sealed end side, in a state where the ultrasonic waveguide 6 is inserted into a test hole 3 excavated on a ground 2 with the opened end side faced downwards; an ultrasonic wave U is transmitted from the ultrasonic transmitting element toward the opened end side; a reflection wave R obtained by reflecting the ultrasonic wave U on the water surface in the ultrasonic waveguide 6 to return is received by an ultrasonic receiving element provided in the interior on the sealed end side of the ultrasonic waveguide 6; and the water level in the ultrasonic waveguide 6 is sequentially measured on the basis of a propagation time required from the transmission of the ultrasonic wave U by the ultrasonic transmitting element until the reception of the reflection wave R by the ultrasonic receiving element, thereby the water permeability coefficient of the ground 2 is calculated.;COPYRIGHT: (C)2015,JPO&INPIT