Q

How accurate is the Pile Integrity Tester (PIT) when used for determining foundation lengths?

A

The accuracy of foundation length is dependent on the accuracy of the wave speed. Since the wave speeds for good quality concrete vary between 3500 m/s (11,500 ft/s) and 4500 m/s (14,500 ft/s) on low strain tests like those performed with the PIT (and the Acoustic Concrete Tester (ACT) - see Question 1018, if an average wave speed of 4000 m/s (13100 ft/s) is used then a maximum variation of plus or minus 12.5 % is possible.