Ekuivalent Diameter of Axisymmetric Model to Plan strain Model

Question

Hello. I want to ask about the column diameter equation from Axisymmetric model to Plan strain model, is it in plaxis or is there any geotechnical expert who recommends a special formula to convert the equivalent diameter from Axisymmetric model to Plan strain mode on 2D plaxis?

Dennis Waterman · Answer

Dear Randy, 
 There is no such thing as a plane strain column, because in plane strain the geometry is the same anywhere in the out-of-plane direction. Hence, in plane strain there cannot be individual columns with soil in between in out-of-plane direction. It will act as a wall. There are conversion formula's from a row of columns to a wall, but you should realize that a wall will never behave like a row of columns for all aspects. So you can make the conversion by making sure the row of columns and the equivalent wall have the same bending stiffness, or axial stiffness, or skin friction, or something else ... but you can never match them all (and often only match 1 of those properties). A single column is either an axisymmetric problem, or a full 3D problem (like with lateral loading), but never a plane strain problem. 
 With kind regards, 
 Dennis Waterman