Method and device for investigation of soil by electric prospecting on an aquatic site

摘要

The invention concerns the investigation by electrical probing of a soil (20) covered by a mass of water (10). Measurements of the apparent resistivity of the environment are made using a system of pairs of aligned electrodes (AB, M1N1, M2N2,...) having different separations and which are disposed on the soil at the bottom of the water, by the injection of a predetermined electric current (I) into the central pair of electrodes (AB), which makes a potential difference (V) appear in one of the other pairs of electrodes (M2N2) which is measured and from which is derived a value of apparent resistivity of the environment subjected to the electric probing. Between the system of electrodes and the mass of water there is interposed a continuous electrically insulating sheet (40), which is dimensioned such that it covers the entire system of electrodes. This sheet constitutes a barrier preventing the injected current from flowing in the water. IMAGE