The Japanese design standard for harbour structures permits to calculate tension in tierods and the maximum bending moment of anchored sheet pile walls with the equivalent beam method, if they have their embedments in sand layers. It assumes that walls are equivalent to simple beams ended at the sea bottom, and that they are supported at sea bottom and connected points with anchors, which are applied under the same loads to walls. It, however, recommends that stresses of walls should be determined with the fixed earth support method, if their embedments are in clay. Because of its complicy, there is need to develope a simple one.
　Assumming that clayey foundation around the embedement are elastic supports, and that their coefficients of lateral subgrade reaction are constant, we can gain simple equations for computing the stress. Comparing calculated bending moment diagrams with directly measured ones at construction sites, we find fairly good accordance between them.