I want to make a 3D numeriacl model of lateral dynamic loads on a driven pile in sand. 1- What material model is the best for the fine dense sand)? 2- How Can I model the interface of soil pile? 3- There are two type of damping for this system (radiational,hysteretic) how can I take into accont? 4- If your response is based on a specifique software please let me know.