DETECTION DEVICE AND METHOD FOR DAMAGE OF WATER SHIELDING SHEET IN DEPOSIT FIELD

摘要

PROBLEM TO BE SOLVED: To accurately detect the damage location of a water shielding sheet on a deposit field without being affected by the variation of electric resistance of a non-isolator such as protection soil where measurement electrodes are placed.;SOLUTION: On a deposit field provided with a water shielding sheet 4 on the ground formed in a concave shape, a plane electrode 3 is placed on one surface side of the water shielding sheet and a current-carrying electrode 8 and a plurality of measurement electrodes 7 are placed on the other surface side of the sheet by way of the non-isolator. An alternating current is impressed between the current-carrying electrode 8 and the plane electrode 3 and phase differences of the alternating current from the electric potentials of the measurement electrodes 7, 7 are measured at a plurality of locations. The variation of the phase differences is analyzed to specify the damage location of the water shielding sheet.;COPYRIGHT: (C)2001,JPO