Hello,
I would recommend using COMBIN39 elements to model the soil-pile interaction. You can define these elements with nonlinear stiffnesses based on your p-y/t-z/q-z curves. The 'Soil Pile Data File' option in the Ocean Environment object allows you to load a MAPDL macro to do this, but you could also just create a Commands object in the Static Structural analysis.
There is some discussion of soil modelling in this thread, maybe you will also find something useful here: https://innovationspace.ansys.com/forum/forums/topic/soil-modeling/
I'm afraid I can't share an MAPDL macro with you on the student forum, but maybe someone else (not an Ansys employee) can.
Mike
You are navigating away from the AIS Discovery experience