Can steel piles be tested with the PIT?


There is limited applicability of PIT on steel piles, due to

  1. their generally high L/D ratio: The difficulties of performing low strain dynamic tests based on the sonic pulse echo or transient response theory on pile with a very large L/D is discussed on Question 1031.
  2. their generally high surface area to volume ratio: This characteristic causes the input wave to be quickly dampened by the surrounding soil.
The PIT test is therefore mostly applicable to determine the integrity of concrete foundation elements. However, successful detections of defects on short (less than 15 m or 50 ft) H-piles in soft soils have been reported by others. PIT is not recommended for open steel pipe piles, unless they are filled with concrete. It should be noted that the PIT equipment and software allows changing the wave-speed and specific weight to those of steel.