METHOD FOR EVALUATING STABILITY OF ROCK LUMP ON ROCK SLOPE BY TAPPING SOUND MEASUREMENT

摘要

PROBLEM TO BE SOLVED: To provide a method for evaluating stability of a rock lump on a rock slope by simple and objective tapping sound measurement that evaluates stability of a rock lump by two-steps evaluation.SOLUTION: A method for evaluating stability of a rock lump on a rock slope includes the steps of: (a) using a tapping sound inspection device to extract a peak indicating the maximum amplitude in a range of 0 to 2000 Hz; (b) determining whether there is a rock lump having a peak indicating amplitude equal to or more than half of the maximum amplitude extracted in the step (a) in a range of 0 to 500 Hz; (c) determining that the rock lump is unstable when the rock lump has the peak indicating amplitude equal to or more than half of the maximum amplitude extracted in the step (a) in the range of 0 to 500 Hz, and determining that stability of the rock lump is not clear when the rock has no such a peak; (d) determining whether the maximum amplitude of the rock lump in the range of 0 to 2000 Hz is equal to or more than twice as large as the maximum amplitude of a bedrock when it is determined that the stability is not clear in the step (c); and (e) determining that the rock lump is unstable when the maximum amplitude of the rock lump in the range of 0 to 2000 Hz is equal to or more than twice as large as the maximum amplitude of the bedrock, and determining that the rock lump is between stable and unstable when the maximum amplitude of the rock lump is less than twice as large as the maximum amplitude of the bedrock.