A Comprehensive Discussion of Piping and Internal Erosion Failure Mechanisms

An embankment dam can fail or experience serious distress if water flows without adequate controls through the embankment itself or through the foundation soil and bedrock on which it rests. A variety of terms have been used to describe the mechanisms by which embankment dams can fail or experience this type of distress. General agreement on the terminology is lacking. One purpose of the paper is to provide a historical discussion of the various terms used for these mechanisms by which dams fail or experience distress from water flow through the structure. This paper proposes a simplified grouping of the various mechanisms, with all of the various terms lumped into only two categories; (1) piping and (2) internal erosion. The mechanisms of piping and internal erosion are split into sub-categories in this discussion. The factors responsible for each identified sub-category of mechanism are discussed. Illustrations accompany the explanations and photographs of failures and distress conditions are included where available. Case histories illustrating each mechanism are cited where they are known. Defensive design measures that are most effective against each mechanism are presented. Much of the paper concentrates on how one can distinguish between piping and internal erosion. 54 pp., multiple figures, 40 references.