UNDERGROUND AIR PERMEABILITY INSPECTION METHOD AND SOIL POLLUTION INVESTIGATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide an underground air permeability inspection method capable of estimating a location under the ground, where a pollutant exists with high possibility, in a pinpoint manner.SOLUTION: Gas pressurized to a first pressure in a pressurization container 79 is supplied to one of drilling pipes 5 inserted into a ground M to a predetermined depth F, so as to be injected into the ground M from a discharge hole bored at the lower end part of the one of the drilling pipes 5. A depressurization time required for the decrease in pressure in the pressurization container 79 to a second pressure lower than the first pressure is measured from the start of the injection. After completion of the measurement, the depth F of the drilling pipes 5 in the ground M is changed to different depth F. After the change of the depth F, the injection of the gas and the measurement of the depressurization time are performed again, so that air permeability of the ground M is inspected.SELECTED DRAWING: Figure 7