Abstract: A device for evaluating integrity of an underground structure by using electromagnetic waves includes a plurality of main reinforcing bars arranged in a vertical direction in an underground structure, a plurality of measurement cables extending vertically to be adjacent to the main reinforcing bars, respectively, at least one impedance change unit which is provided on each of the measurement cables, is electrically connected to the measurement cable, and has a characteristic impedance different from a characteristic impedance of the measurement cable, and an electromagnetic wave measurement unit for detecting a change point of a characteristic impedance as a defect point of the underground structure by providing an electromagnetic wave by using, as a signal transmission line, one of the plurality of measurement cables and one of the plurality of main reinforcing bars, or one pair of measurement cables selected from the plurality of measurement cables.

Abstract: A device for evaluating integrity of an underground structure by using electromagnetic waves includes a plurality of main reinforcing bars arranged in a vertical direction in an underground structure, a plurality of measurement cables extending vertically to be adjacent to the main reinforcing bars, respectively, at least one impedance change unit which is provided on each of the measurement cables, is electrically connected to the measurement cable, and has a characteristic impedance different from a characteristic impedance of the measurement cable, and an electromagnetic wave measurement unit for detecting a change point of a characteristic impedance as a defect point of the underground structure by providing an electromagnetic wave by using, as a signal transmission line, one of the plurality of measurement cables and one of the plurality of main reinforcing bars, or one pair of measurement cables selected from the plurality of measurement cables.