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| | Abstract | | For safety evaluation for seepage of a river embankment, its permeability is measured with in-situ or laboratory soil core sample tests for boreholes drilled on the embankment or simply estimated from an average grain size using an empirical relation of permeability and a grain size such as the Creager's equation. Geophysical data can be used for effectively constructing an entire permeability model of a generally complex embankment. We attempt to employ the Koseny-Carman equation for estimating permeability with porosity and grain size derived from S-wave velocity and resistivity obtained with well log data and the seismic and electric surveys on the embankment. For saturated soils such as subsoils below the groundwater table, porosity is estimated from resistivity with the Archie's equation, and the grain size is estimated using a rock physics model with S-wave velocity and resistivity. For unsaturated soils such as dyke body and sobsoils above the groundwater table, the grain size and porosity are estimated from resistivity and a rock physics model, respectively. Estimated permeability for saturated soils is well consistent with measured data, while that for unsaturated soils does not so well agree to measured data. |
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