Prediction of scour in overtopped floodwalls using JET and EFA

Erosion due to water overtopping of floodwalls is one of the main causes of levee failures during storms events. Prediction of scour rate and depth in fine grained material has always been a critical issue for engineers. Performing full scale erosion tests on geo-structures like levees can be difficult and expensive. However, JET and EFA test are alternative tests to determine the scour potential of a soil. JET can be conducted both in the lab and in-situ, while EFA is conducted in the laboratory. In this study, a series of laboratory JET, EFA, and lab-scaled levee-floodwall erosion tests have been conducted on material retrieved from Mississippi River bank. The results of erosion rate on these soils have been compared. In addition, a correlation is proposed to estimate the erosion rate that occurs during floodwall overtopping in crest of levees based on JET and EFA results for soils with various compactions and plasticity indices.