Can you test a caped pile?

This week, we were again asked if a pile that has been caped can be tested with the PET pile integrity tester. You can test it, yet the challenge is figuring out the echo signal from the toe or the flaw from the echo noise that the cap creates. So, our overall recommendation is not to test a pile that has been caped.

We have used our Pilewave simulator to better understand this scenario's limitations, and you are invited to play with it as well. See the samples below that represent the problem and test limitations. It proves that testing a pile that has been caped puts the reliability of your report in danger for:

• False positive (Missing important defects) - Wrongly trusting defective piles - DANGER

• False negative (Wrongly calling a good pile defective)

These are examples of reflectograms we received from the Pilewave simulator. They are live - click them to try.

The shape of the tested pile can be seen below

A - Pile with cap - with necking- (Possible false negative)

B - Pile with cap - without necking - (Possible False positive)

C - Pile without cap - with necking (True positive)

D - Pile without cap - without necking (True negative) for reference

Below, you can see the shape of the different piles.

A B C D