PITCan the Pile Integrity Tester be used to evaluate the length and defects of piles supporting existing structures?
Yes, under favorable conditions it is possible to test piles under existing structures with the PIT. In order for the test to succeed, the pile itself must have a relatively solid concrete surface to channel the impact (this can be a solid section concrete pile, or a concrete filled steel pipe). If the pile is made out of concrete and the structure is very light relative to the pile or shaft (for example a cell tower where the tower legs are significantly smaller than the shaft), then the structure is almost inconsequential provided there is access to the concrete at the top of the pile or shaft. The PIT test may be performed as usual. If the structure is relatively massive, then the shorter the vertical dimension of the cap, the better it is for the test. One accelerometer placed concentrically above the pile may yield good results. Most likely, however, a Two Velocity Test will provide better results. The Two Velocity Test involves placing two different accelerometers along the shaft
