1)Pile defects: Comprehensive determination is made by sound speed critical value, amplitude critical value and PSD criterion.2) Pile uniformity is divided into A, B, C and D levels according to the discrete coefficient of sound technology.
1)Pile defects: Comprehensive determination is made by sound speed critical value, amplitude critical value and PSD criterion.2) Pile uniformity is divided into A, B, C and D levels according to the discrete coefficient of sound technology.<br>