Abstract: The concepts of piping’s criticality and piping tending to breach dyke were presented in the light of some cases of piping happened in the Jingjiang stretch of Yangtze River dyke and the studies of piping modelling. The concept of piping’s criticality is conducive for the quantitative research on factors affecting piping’s evolution. Special influence factors on criticality of piping include: flood process, water level in the protected area, piping’s location, structure and soil properties near the piping and along its evolution path, as well as seepage control measures. Classifying piping according to criticality lays an important foundation for the separate treatment of different piping types,and is also a vital approach to improving the pertinence and scientific decision of piping treatment. Generally, piping in the embankment, and those extending fast to the embankment, should be recognized as piping tending to breach dyke, which should be followed with treatment measures to hinder the evolution, or emergency plans implemented immediately.

Key words: dyke, criticality of piping, piping tending to breach dyke, modelling, treatment measure, Jingjiang stretch of Yangtze River dyke, seepage deformation