Study and application on a new method of testing piles by the character of waves train for single-impact--measuring quality of a pile
波列振幅衰减测桩法的研究与应用(Ⅱ)——桩身成型质量的检测

From analyzing characteristic of wave and vibration and coda we take a new methods by which quality of pile is evaluated. Quality of pile will be excellent if period of train is equality and small, and attenuation of amplitude is more quickly, and there is not phase of reflect-wave; There are defects (for example it occurs fracture or diameter become smaller) in the pile if attenuation of amplitude is slower, and the period of train is bigger much, and there is phase of reflect-wave for wave train recorded at top of pile by single impacting. This is especially efficiency for determining defects under top of pile 5 m. Otherwise quality of pile is evaluated by dynamic PS-curves. Quality of pile will be excellent if PS-curve is more smooth. There are defects in the pile if PS-curve is zigzag and twist. Of course, degree of defect is confirmed by decreasing amount of bearing capacity.