PDA High Strain Dynamic Load Test / Pile Driving Analyzer 1

[struggle67]

Hi everyone

Any PDA expert here? Is PDA reliable? Can someone please recommend any literature on PDA or any work examples to calculate pile soil resistance from PDA results?

I also came across this formula below. Quite a lot of questions popped into my head.

How was this formula derived? What do the 1st term force term and 2nd velocity x pile impedance represent? I understand that F(t1)can be obtained from the strain gauge attached near the top of pile but how do I get this F(t1+2L/c) value? Why are two forces in the first term added, two velocities subtracted and divided by two?

Thanks for your sharing in advance

 

[centondollar]

PDA is based on solving the wave equation (1D rod with time-dependent changes in axial stress and deflection) in real-time by analyzing the vibration of the pile being driven. It is used in dynamic pile testing during pile driving for purposes of verifying that required capacity is reached and is generally more accurate than analysis by empirical methods, closed-form static equations or static pile testing. More details can probably be found in the literature.