I am trying to calculate the deflection of rigid sheet pile wall rotating about a pivot point. I tried: From the earth pressure diagram, an expression for bending moment is written, then from the euler bernoulli theory, a differential equation for bending moment is written. As we know, further integration of bending moment give rotation and deflection which can be solved by substituting the boundary condition. The boundary condition will be related to deflection and rotation. For Deflection I am sure that deflection at the pivot point will be zero. But what will be the boundary condition for rotation?