| Popis: |
This paper describes an attempt to quantify flaw detectability in cross hole ultrasonic testing of piles. To this end we constructed a bored pile with access tubes and three pre-fabricated flaws, and then tested it with the CHUM ultrasonic instrument. We analyzed the results and presented them in the conventional one-dimensional format, as well as in two- and three-dimensional tomographic images. We then compared the results with those of a finite element model which showed similar effect of the flaws. We concluded that a flaw is usually detectable by this method only if its size exceeds one-third of the access tube spacing. In addition, the use of advanced tomographic techniques may enhance flaw detectability. |
