LOW STRAIN DYNAMIC TEST
Also known as Pulse Echo Test (PET) or Pile Integrity Test (PIT), this testing procedure aims to determine the general characteristics of existing piles such as depth or major defect. The non-destructive test can be performed on CFA, Bored, driven-concrete or timber piles. If major defects exist, test results may be interpreted to estimate their magnitude and location.
The test consists of attaching one or two accelerometers to a pile and using a hand-held hammer to impact the pile top. The PIT collects the acceleration data and displays curves that reveal any significant changes in a cross section that may exist along the shaft. The impact of the hammer generates a stress wave that propagates down the foundation and reflects back up. The accelerometer collects data that reveals the pattern of wave propagation and reflection.
PIT tests may also help estimate the depth of the pile toe (the pile length) if the pile is intact with embedment less than 30 times the pile diameter. Initial PIT data is evaluated in the field and later transferred to a computer for further analysis.
