Modelling plaxis 2D and 3D

Question

Hello plaxis team, Im modelling a slope on plaxis 2D and plaxis 3D. My input is exactly same for material and geometry. But why in plaxis 3D the plastic phase is failure? Can you help me to get this things right? 
 Thnk you

Dennis Waterman · Answer

Dear Muhammad, 
 The input is probably not entirely the same because the meshes will be different. What is the safety factor in 2D? If it's almost 1, then a small difference in the mesh can make the difference between just not failing in 2D and just failing in 3D. Be aware that for instance in 3D the finite elements are always 2nd order elements whereas in 2D the finite elements are by default 4th order elements (15-noded). 
 With kind regards, 
 Dennis Waterman