Assessment of Unsaturated Zones with Ground Penetrating Radar with Modulating Frequency in Tono Mine

Toida, Masaru*; Suyama, Yasuhiro*; Kaoru, Nagoya*; Atsumi, Hiroyuki*

JNC TJ7440 2003-001, 92 Pages, 2003/03

JNC-TJ7440-2003-001.pdf:5.66MB

The TDR (Time Domain Reflectmetry) wave analysis method has been developed for measuring unsaturated zones by TGC in Tono mine. The new packer type probe of the TDR wave analysis method has already been made by TGC. But it is impossible for the TDR wave analysis method to estimate distribution of unsaturated zones between boreholes. In the meantime, to overcome the reached penetration depth of the sedimentary rock, the ground penetrating radar with modulating frequency was developed and could have the ability of interpretation of water content distribution from electromagnetic velocity. This report summarizes as follows: 1)An electromagnetic wave tomography with modulating frequency could measure the dielectric constant distribution with a good correlation between the tomography and the TDR wave method at the second measurement gallery. Therefore it recognized that the tomography has a high possibility to interpolate the TDR wave method's results between boreholes. 2)The ground penetrating radar with modulating frequency could measure the dielectric constant, which has a good relationship with water content distribution, at the NATM gallery. Therefore it recognized that the radar has a high possibility to get information concerning water content distribution.