Identification of defects in piles with high slenderness ratios using dynamic response to impulse loads

The main objective of this paper is to evaluate the capabilities of the non-destructive impact-response method in detecting the existence of defects in piles with high slenderness ratio. The impact-echo technique was developed many years ago for non-destructive detection of defects in piles and structures. However, it is recognised that this method could be applied confidently for piles with length/diameter relationship up to 20. In the last years, with the development of hardware in computers and sensors, it is now possible to use this method for piles with high slenderness ratio. In this paper, piles of length/diameter relationship of about 40 are studied. A numerical-experimental study was carried out. It was shown that the results of the experiment were in agreement with those of the numerical studies and the accuracy of the impact-echo method was influenced by the type, size and location of the defects. Taking into account the uncertainties related to the studied problem, the obtained results preliminarily allow consider this NDT methodology as a promissory alternative to detect defects in piles with high slenderness ratio.