| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the diagnosis of an underground pile and a construction which are damaged by an earthquake by receiving a reflection wave resulting from a blow, and filtering it to analyze a reflection component in a required domain for judging the size and position of the defect. SOLUTION: A blow device 1 such as a hammer strikes an underground construction 2 such as a pile, and a produced reflection wave 3 is received through a receiver 4. The blow device 1 and the receiver 4 are connected to a measurement record device 5 for recording obtained data. In addition, the measurement record device 5 may be connected to a computer 6, and the data can be analyzed by the computer 6. Only the frequency zone of the reflection wave corresponding to the size of a crack wanted to be diagnosed is watched, and the other frequency component is removed by filtering the reflection wave, and a frequency component corresponding to the width of a crack and the degree of damage which are wanted to be detected is extracted, and the defect of the reflection wave is judged by catching the component of reflection wave. |
