HR: 1340h
AN: H23A-1111    [Abstracts]
TI: Characterization of Physical and Hydro-Geological Properties of Kanamaru Research Site in Japan
AU: * Takeda, M
EM: mikio-takeda@aist.go.jp
AF: Research Center for Deep Geological Environments, National Institute of Advanced Industrial Science and Technology, Central 7, 1-1-1, Higashi, Tsukuba, 305-8567 Japan
AU: Zhang, M
EM: m.zhang@aist.go.jp
AF: Research Center for Deep Geological Environments, National Institute of Advanced Industrial Science and Technology, Central 7, 1-1-1, Higashi, Tsukuba, 305-8567 Japan
AU: Takeno, N
EM: n.takeno@aist.go.jp
AF: Research Center for Deep Geological Environments, National Institute of Advanced Industrial Science and Technology, Central 7, 1-1-1, Higashi, Tsukuba, 305-8567 Japan
AU: Watanabe, Y
EM: Yoshio.Watanabe@aist.go.jp
AF: Research Center for Deep Geological Environments, National Institute of Advanced Industrial Science and Technology, Central 7, 1-1-1, Higashi, Tsukuba, 305-8567 Japan
AB: Establishing the comprehensive knowledge of applicability of the methods for investigating hydraulic properties of low permeability geologic strata is an urgent issue for supporting regulation of geological disposal of nuclear waste in the near future. As a beginning of this work, a systematic examination of various kinds of techniques for hydro-geological surveys has been started in Kanamaru Research Site in Japan. This paper briefly introduces the research plan and preliminary results obtained from the first year of investigation. The survey techniques include borehole excavation, borehole imaging, gamma-ray, caliper, acoustic, electrical resistivity and density loggings, permeability tests and flow direction measurement using a single borehole, permeability tests and flow direction measurement using multi boreholes, etc. Preliminary findings can be summarized as follows: (1) The stratigraphy at the survey area consists of topsoil, debris sediments, sandstone, mudstone, conglomeratic sandstone, mudstone, arkose sandstone, and granite. High uranium concentrations are detected at lower portion of the conglomeratic sandstone by gamma-ray logging. (2) The survey area is located at a slope inclined from the north to the south, and the dominant groundwater flow is considered to be in the direction form the north to the south. And the downward flow was also recognized by the flow direction measurements and water quality logging. (3) Hydraulic conductivities derived from permeability tests using a single borehole were in the range of 5E-10 to 1E-7 m/s. The hydraulic conductivities of the same lithology derived from different boreholes varied, and the discrepancies were up to an order. This result indicates that the formations in the survey area have hydraulic heterogeneity in both the vertical and horizontal directions. (4) On the whole, stratum with fast velocity of elastic wave showed large resistivity and low permeability. The degree of correlation between the hydraulic and physical properties was different for each stratum.
DE: 5100 PHYSICAL PROPERTIES OF ROCKS
DE: 5114 Permeability and porosity
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1894 Instruments and techniques
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting