Would appreciate information on available non-destructive test methods (and likely accuracies) for deteremining insitu pile lengths. This testing is required as part of an initial investigation for dispute resolution between client and contractor. The second option will most likely involve actual excavation beside suspect piles. Availability of methods in Australia would be appreciated and I thank all those in advance for their assistance.
Pile Dynamics makes several devices for electronic measurments. See more information at www.pile.com
Pile Driving Analyzer needs you to impact the pile with a large weight (pile driving hammer, or large drop weight). If you can move the pile, you will probably see a toe reflection. If it is a steel pile so you know the wavespeed (constant 5123 m/s) then you can calculate length. For concrete where wavespeed is variable, you can estimate length within about ten percent.
Pile Integrity Tester uses a small hand held hammer to hit free pile. Pile must be concrete, and there are other restrictions.
You might contact Dr Julian Seidel at Monash University in Melbourne, Victoria as he knows methods and can advise on applications and refer you to various test agencies with the necessary equipment.