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André Revil - One of the best experts on this subject based on the ideXlab platform.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Soueid Ahmed, A. Coperey, Ludovic Ravanel, Rajesh Sharma, Ns Panwar
    Abstract:

    Abstract The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isere, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Coperey, Ludovic Ravanel, Rajesh Sharma, A Soueid Ahmed, Ns Panwar
    Abstract:

    The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isère, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

  • A Geophysical index to map alteration, permeability, and mechanical properties within volcanoes. Application to the soft volcanic rocks from Whakaari/White Island (New Zealand)
    Journal of Volcanology and Geothermal Research, 2020
    Co-Authors: André Revil, A. Coperey, Michael Heap, Lucille Carbillet
    Abstract:

    The alteration of soft volcanic rocks (i.e., characterized by a low uniaxial compressive strength b35 MPa) can change their permeability and mechanical strength. We built an alteration indicator based on porosity and cation exchange capacity (CEC) to connect the degree of alteration of soft volcanic rocks to their permeability and uni-axial compressive strength. The proposed empirical petrophysical relationships are validated using a dataset of 62 samples from Whakaari/White Island (New Zealand). Since porosity and CEC can be imaged with induced polarization , this Geophysical Method can be used to map permeability and mechanical properties for near-surface formations at active volcanoes worldwide.

  • Spectral induced polarization porosimetry
    Geophysical Journal International, 2014
    Co-Authors: André Revil, Nicolas Florsch, Christian Camerlynck
    Abstract:

    Induced polarization is a Geophysical Method looking to image and interpret low-frequency polarization mechanisms occurring in porous media. Below 10 kHz, the quadrature conductivity of metal-free sandy and clayey materials exhibits a distribution of relaxation times, which can be related to the pore size distribution of these porous materials. When the polarization spectra are fitted with a Cole-Cole model, we first observe that the main relaxation time is controlled by the main pore size of the material and that the Cole-Cole exponent c is never much above 0.5, a value corresponding to a Warburg function. The complex conductivity is then obtained through a convolution product between the pore size distribution and such Warburg function. We also provide a way to recover the pore size distribution by performing a deconvolution of measured spectra using the Warburg function. A new dataset of mercury porosimetry and induced polarization data of six siliciclastic materials supports the hypothesis that the Cole-Cole relaxation time is strongly controlled by the pore size, and especially the characteristic pore size corresponding to the peak of the pore size distribution from mercury porosimetry. The distribution of the pore throat sizes of these materials seems fairly well recovered using the Warburg decomposition of the spectral induced polarization spectra but additional data will be needed to confirm this finding.

  • HOW USEFUL IS SPECTRAL INDUCED POLARIZATION
    23rd EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, 2012
    Co-Authors: André Revil
    Abstract:

    Induced polarization represents the accumulation of charge carriers (electrons and ions) in a porous material and their back-diffusion in their concentration fields. This Geophysical Method can be carried out either in the time domain or in the frequency domain. In principle frequency domain induced polarization (SIP) may offer a powerful Geophysical Method to solve a number of hydrogeochemical problems including imaging permeability distribution and a reconnaissance tool for contaminant plumes. In practice, this Method is limited by a number of issues including electromagnetic coupling above 100 Hz, the mutiplicity of polarization contributions that make the interpretation delicate, flat spectra that are poorly informative in systems characterized by a broad distribution of relaxation times, the long duration needed to take a snap-shot and so on. Therefore it is legitimate to wonder under what conditions spectral induced polarization is a powerful Method, ... or not.

Ns Panwar - One of the best experts on this subject based on the ideXlab platform.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Soueid Ahmed, A. Coperey, Ludovic Ravanel, Rajesh Sharma, Ns Panwar
    Abstract:

    Abstract The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isere, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Coperey, Ludovic Ravanel, Rajesh Sharma, A Soueid Ahmed, Ns Panwar
    Abstract:

    The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isère, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

A. Coperey - One of the best experts on this subject based on the ideXlab platform.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Soueid Ahmed, A. Coperey, Ludovic Ravanel, Rajesh Sharma, Ns Panwar
    Abstract:

    Abstract The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isere, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Coperey, Ludovic Ravanel, Rajesh Sharma, A Soueid Ahmed, Ns Panwar
    Abstract:

    The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isère, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

  • A Geophysical index to map alteration, permeability, and mechanical properties within volcanoes. Application to the soft volcanic rocks from Whakaari/White Island (New Zealand)
    Journal of Volcanology and Geothermal Research, 2020
    Co-Authors: André Revil, A. Coperey, Michael Heap, Lucille Carbillet
    Abstract:

    The alteration of soft volcanic rocks (i.e., characterized by a low uniaxial compressive strength b35 MPa) can change their permeability and mechanical strength. We built an alteration indicator based on porosity and cation exchange capacity (CEC) to connect the degree of alteration of soft volcanic rocks to their permeability and uni-axial compressive strength. The proposed empirical petrophysical relationships are validated using a dataset of 62 samples from Whakaari/White Island (New Zealand). Since porosity and CEC can be imaged with induced polarization , this Geophysical Method can be used to map permeability and mechanical properties for near-surface formations at active volcanoes worldwide.

Rajesh Sharma - One of the best experts on this subject based on the ideXlab platform.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Soueid Ahmed, A. Coperey, Ludovic Ravanel, Rajesh Sharma, Ns Panwar
    Abstract:

    Abstract The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isere, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Coperey, Ludovic Ravanel, Rajesh Sharma, A Soueid Ahmed, Ns Panwar
    Abstract:

    The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isère, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

Ludovic Ravanel - One of the best experts on this subject based on the ideXlab platform.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Soueid Ahmed, A. Coperey, Ludovic Ravanel, Rajesh Sharma, Ns Panwar
    Abstract:

    Abstract The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isere, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.

  • Induced polarization as a tool to characterize shallow landslides
    Journal of Hydrology, 2020
    Co-Authors: André Revil, A. Coperey, Ludovic Ravanel, Rajesh Sharma, A Soueid Ahmed, Ns Panwar
    Abstract:

    The development of shallow landslides is strongly connected to the changes in the water content of soils on hillslopes, their clay content and permeability distribution, which, in turn, are playing an important role regarding their hydro-mechanical properties. A non-intrusive Geophysical Method able to map these properties would be very helpful. The most common geoelectrical Method, DC (Direct Current) resistivity, cannot be used as a stand-alone technique for this purpose since it depends on two contributions (bulk and surface conductivities), which depend on the water content and the cation exchange capacity (CEC) of the material. Induced polarization is a Geophysical Method that can be now used to complement DC resistivity in providing key material properties that can be used to diagnose potential risks for failure. We first recall the basic principles behind the induced polarization Method from laboratory to field scales and key findings in the underlying petrophysics needed to jointly interpret electrical conductivity and normalized chargeability tomograms. Then, we apply these relationships to a field survey carried out over a shallow landslide at Claix (Isère, France), close to Grenoble. A 3D induced polarization survey was carried out and interpreted in terms of the clay content, water content, and permeability distributions. We demonstrate that the landslide is associated with a channel of high water content corresponding with the presence of travertine, a flow-path, and a permeability barrier downslope corresponding to the presence of plastic clays. This study demonstrates that induced polarization can be used to characterize the impacted volume and therefore might have been useful to map the area before the landslide to assess the possible risk of failure. This Methodology could play a key role in mitigation planning.