There was a download of DynaPile 1.0 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. This program was originally designed by Ensoft, Inc. The most popular version of the tool 1.0. We recommend checking the downloaded files with any free antivirus. DynaPile lies within Education Tools, more precisely Science Tools.
From the developer:
Program DynaPile was developed to compute the dynamic stiffness of single piles or pile groups. The piles can be either floating piles or end-bearing piles. Vertical, horizontal and rocking dynamic stiffnesses will be generated by the program. The program will also generate the group reduction factors for pile groups under small excitation conditions.
You may want to check out more software, such as Avantage BPM Foundation, Adding Machine or PC-Display, which might be similar to DynaPile.