Experimental Study on the Piping Erosion Process in Earthen Embankments

Abstract

Experimental results on the piping erosion process in an earthen embankment emplaced in a laboratory flume are reported in this paper along with the details of the experimental set-up and procedures. A mixture of sand, silt, and clay with different compaction rates is used for constructing the embankment. An image processing technique is successfully applied to track the erosion process from both side-looking and bottom-up views. The paper discusses changes in the depth, area, and volume of erosion during the piping phenomenon in a model embankment using a visual technique. The results show that increasing compaction of the construction layers significantly increases the time required for erosion but has little effect on the final-average depth of erosion. The ratio of the average depth of erosion to the average bottom width of piping is close to one at different time intervals. Exponential equations to estimate the depth of erosion, side area of the piping zone, and volume of eroded material are presented. Two approaches are investigated to estimate the volume: the approach based on the processing of images from both the side–view and bottom–view gives more accurate results than that based on processing the side–view.