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Evaluating the Sealing Efficiency of Flood Embankments with the Use of Geophysical Methods
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Near Surface 2008 - 14th EAGE European Meeting of Environmental and Engineering Geophysics, Sep 2008, cp-64-00110
- ISBN: 978-90-73781-56-6
Abstract
Flood embankments, usually constructed with the use of local sandy-gravel stuff, usually do not fulfil their assignments during long time flood overflowings, so they need to be sealed. One of the sealing methods is injection of polymineral clay solution. As a result of injection a continuous impermeable screen within the embankment body shall be created. Such requirement is often not fulfiled because of inhomogeneity of the embankment stuff. Evaluation of efficiency of sealing works then consists in verification of integrity of the manufactured screen. Basing on electric resistivity variation between embankment soil and screen surveys with tomography mapping of electric resistivity distribution within the screen plane were chosen to solve this task. Poor sealed places are characterised by high electric resistivities there. Measurements are carried out in several series, before injecting works in order to determine electric resistivity distribution within soil and as a baseline for the succeeding measurement series, and after sealing, in order to determine changes caused by injection. Example of such works carried out along a selected section of embankments of Warta river at Kostrzyn is presented.