| 摘要 |
PURPOSE:To determine the path of water leakage quickly, by putting a tracer into the underground water in an investigating boring hole, and sequentially measuring the electric conductivity state of current flowing the underground water with the elapse of time in a plurality of boring holes, which are provided along the crown of an embankment. CONSTITUTION:When a water leaking part 4 is found in an outer slant surface 3 of an enbankment 1, a plurality of boring holes 6 are provided to a depth lower than the underground water level in parallel along a crown 5 of the embankment 1. One investigating boring hole 8 is provided to the depth lower than the ground water level in a slant surface 7 of the water reserving side of the embankment 1. A current is sequentially conducted to a pluraity of lead wires 10 at a specified time interval by a timer. The electric conductivity of the underground water 15 in the respective boring hole 6 is sequentially measured by a conduction meter 13 and recorded by a recorder 14. Under this state, salt is put in the underground water in the investigating boring hole 8. Then the salt concentration of the underground water in one of the plurality of the boring holes 6 is increased and the electric conductivity is changed. The path of the water leakage can be quickly acknowledged by the change in electric conductivity. |
