Stability of Embankment Foundations

The analyses made in connection with the design of two large rock-fill embankments proposed as part of the now discontinued Passamaquoddy Tidal Power Project, included certain unusual studies of stress distribution in clay foundations and the character of embankment settlement resulting from foundation over-stress. The report of these studies, which is presented herein, is intended to describe the general nature of the findings and to draw attention to a possible need for the extension of analytical methods (which, at present, are chiefly concerned with designing embankments so as to prevent over-stress of the clay type of foundations) to new methods in which a condition of overstress is accepted for economic reasons, and the extent of the resulting embankment settlement i s computed as the basis for cost estimates.