Hello Iam a BSc student i work on plaxis 3d how i could make a circular soil sample instead of rectangular
Dear Hamid,
I would recommend you checking our Tutorial examples and Reference manual for more information about PLAXIS 3D.
https://communities.bentley.com/products/geotech-analysis/w/plaxis-soilvision-wiki/45388/tutorials-plaxis-3d
The above will help you understand the PLAXIS functionality and give you a nice start for using the program.