Internal Erosion and Fluidisation of Granular Materials - A Review.

An understanding of the failure mechanisms induced by seepage flow is important from both a practical and a theoretical perspective. Conventionally, failure arising from seepage flow is considered a consequence of piping (internal erosion), according to seepage theory, at a critical hydraulic gradient of around 1. However, failures arising from seepage flow are more complex and might involve different mechanisms than originally suspected. This research paper reviews the published literature and identifies the most up-to-date findings to make recommendations for future research. We present experimental evidence that indicates that internal fluidisation in granular soil can occur in many unseen situations when subjected to localized flow that does not necessarily adhere to Darcy's law. Ultimately, we conclude that while there has been substantial research to investigate and explain the mechanism(s) of failure of granular materials subject to vertical seepage flow, to the best of our knowledge, no research studies have simulated the potential failure mechanism of a granular bed triggered by lateral seepage flow, which might arise, for instance, in the case of leakage via a defect in an earth dam or a sheet pile retaining wall. Therefore, further research is needed to improve our understanding of failure mechanisms associated with lateral seepage flow. [ABSTRACT FROM AUTHOR]